Novel stabilized nucleoside phosphates and their analogues

Abstract

The present disclosure includes oligonucleotide and nucleic acid compositions having stabilized phosphate moieties, represented by formula (Ia) and formula (Ib), wherein X is a 3- to 5-membered cycloalkyl, -CHCH-, a 3- to 5-membered heterocycle, and -CH 3 CH 3 - is selected from. [Formula 1] TIFF2025533554000074.tif32128

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 376,579, filed September 21, 2022, the entire contents of which are incorporated herein by reference in their entirety.

[0002] FIELD OF THE INVENTION The present disclosure relates generally to the fields of chemistry, molecular biology, and genetic engineering, including oligonucleotide and nucleic acid moieties and molecules useful for stabilizing oligonucleotides, as well as the synthesis and use of oligonucleotide and nucleic acid moieties and molecules. [Background technology]

[0003] Efficient gene silencing by RNAi in vivo requires recognition and binding of the 5'-phosphate of the siRNA guide strand by Argonaute proteins. Incorporation of 5'-E-vinyl-phosphonate 5'-(E)-VP has been demonstrated to increase siRNA accumulation, prolong the duration of silencing, and protect siRNA from 5'-3'-exonucleases. ACS Chem. Biol. 2013, 8:7, 1402-1406. Structural studies indicate that the 5'-binding site in the MID domain of human Argonaute-2 (hAgo-2) can adjust key binding residues to compensate for changes introduced by modified nucleotides. Nucleic Acids Res. 2017, 45:6, 3528-3536.

[0004] There remains a high unmet need for alternatives to 5'-(E)-VP. Summary of the Invention

[0005] Thus, there is an unmet need for alternatives to 5'-(E)-VP. The present invention fulfills this need by providing novel alternatives to 5'-(E)-VP.

[0006] In a general aspect, the present disclosure provides a compound of formula (Ia) or (Ib):

[0007] [ka] A compound represented by the formula: In the formula, X is a 3- to 5-membered cycloalkyl, —CHCH—, a 3- to 5-membered heterocycle, or —CHR 3 CHR 3 -, Y is selected from O or NR', R' is a counterion, H, or a protecting group, Z is selected from H, a counterion, an activating group, and an oligonucleotide, A and the connecting dashed line are optional, and if present, A is selected from O, S, and CR 4 R 4 B is a nucleobase; each R is independently selected from an oligonucleotide, a counterion, H, and a protecting group, e.g., C1-C5 alkyl and POM or C1-C5 alkyl; and each R 1 and R 2 is independently selected from H, F, OH, and optionally substituted O-alkyl, or R 1 and R 2 forms an optionally substituted oxetine, and each R 3 is independently selected from C1-C3 alkyl, and each R 4 is independently selected from H, F, and C1-C5 alkyl; R 5 and R 6 and the other is H, with the proviso that when A is O, X is not -CHCH-, and when X is cyclopropyl, at least one of A or Y is not O. In some embodiments, when A is present, X is selected from 3- to 5-membered cycloalkyl, -CHCH-, 3- to 5-membered heterocycle, and -CHR 3 CHR 3 - selected from R 1 and R 2 are not H, respectively.

[0008] In some embodiments, the compounds represented by formula (Ia) and (Ib) are

[0009] [ka] It is expressed as:

[0010] In some embodiments, the compounds of Formula (Ia) and (Ib) are

[0011] [ka] It is expressed as:

[0012] In some embodiments, the compound of Formula (Ia) is

[0013] [ka] In some embodiments, X is cyclobutyl. In some embodiments, cyclobutyl is represented by

[0014] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. In some embodiments, X is -CHR 3 CHR 3 - and R 3 In some embodiments, X is

[0015] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. In some embodiments, X is selected from:

[0016] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. 2 is an optionally substituted oxetine. In some embodiments, X is -CHCH-. In some embodiments, Y is O. In some embodiments, Z is an activating group. In some embodiments, the activating group is

[0017] [ka] where the dashed lines represent the connection points to adjacent atoms. In some embodiments, Z is an oligonucleotide. In some embodiments, the oligonucleotide is the antisense strand of an RNA, preferably the antisense strand of an siRNA. In some embodiments, the 5' end of the oligonucleotide is linked to Y. In some embodiments, A is O. In some embodiments, A is CH2 or CHF. In some embodiments, X is -CHCH-. In some embodiments, B is uracil or thymine. In some embodiments, R 1 is H and R 2 is OMe, OEt, MOE, or F. In some embodiments, R is a protecting group, e.g., POM, Et, and Z is an activating group. In some embodiments, R is H and Z is an oligonucleotide. In other embodiments, R and Z are each an oligonucleotide, e.g., a compound of the present disclosure is not at the terminus of an oligonucleotide. In some embodiments, R 5 is XP(O)(OR). In other embodiments, R 6 is XP(O)(OR)2.

[0018] In some embodiments, the compound is

[0019] [Table 1] or a compound of the Table where the nucleobase is thymine or cytosine. 2 is -OMe. In some embodiments, R is Et and Z is an activating group. In some embodiments, R is H or a counterion and Z is an oligonucleotide.

[0020] Other aspects, features, and advantages of the present invention will become apparent from the following disclosure, including the detailed description of the invention and its preferred embodiments, and the appended claims. DETAILED DESCRIPTION OF THE INVENTION

[0021] In the "Background" section and throughout this specification, various publications, articles, and patents are cited or described, and each of these references is incorporated herein by reference in its entirety. The discussion of documents, operations, materials, devices, articles and the like which is included in the specification is for the purpose of providing a context for the present invention. Such discussion is not an admission that any or all of these items constitute part of the prior art to any invention disclosed or claimed.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Unless otherwise defined, certain terms used herein have the meanings set forth herein. All patents, published patent applications, and publications cited herein are incorporated by reference as if set forth herein in their entirety.

[0023] It should be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0024] Unless otherwise specified, all numerical values, such as percent sequence identity or percent sequence identity ranges, described herein are understood to be modified in all instances by the term "about." Thus, numerical values ​​typically include ±10% of the stated value. For example, a 10 mg dosage includes 9 mg to 11 mg. As used herein, the use of numerical ranges explicitly includes all possible subranges, including integers and fractions of values ​​within that range, and all individual numerical values ​​within that range, unless the context explicitly dictates otherwise.

[0025] As used herein, the connective term "and / or" between multiple listed elements is understood to encompass both individual and combined alternatives. For example, when two elements are connected by "and / or," the first alternative refers to the first element being applicable without the second element. The second alternative refers to the second element being applicable without the first element. The third alternative refers to the first element and the second element being applicable together. Any one of these alternatives is understood to be within the meaning and, therefore, meets the requirements of the term "and / or" as used herein. The simultaneous applicability of two or more of the alternatives is also understood to be within the meaning and, therefore, meets the requirements of the term "and / or."

[0026] Unless otherwise indicated, the term "at least" preceding a series of elements should be understood to refer to every element in the series. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the present invention.

[0027] Throughout this specification and the claims that follow, unless the context otherwise requires, the terms "comprise" and variations such as "comprises" and "comprising" will be understood to mean the inclusion of the specified integer or step or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps. As used herein, the term "comprising" can be replaced with the terms "containing" or "including," or, as sometimes used herein, can also be replaced with the term "having."

[0028] As used herein, "consisting of" excludes any element, step, or ingredient not specified in the claim element. As used herein, "consisting essentially of" does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. Whenever used herein in the context of aspects or embodiments of the present invention, any of the above terms "comprise," "contain," "include," and "have" can be substituted with the terms "consisting of" or "essentially consisting of" in order to vary the scope of the disclosure.

[0029] As used herein, "nucleobase" can include unmodified, natural, or modified nucleobases. "Unmodified" or "natural" nucleobases include the purine bases adenine (A) and guanine (G), and the pyrimidine bases thymine (T), cytosine (C), and uracil (U). "Modified nucleobases" include 5-methylcytosine (5-me-C), 5-hydroxymethylcytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkyl derivatives of adenine and guanine, 2-propyl and other alkyl derivatives of adenine and guanine, 2-thiouracil, 2-thiothymine, and 2-thiocytosine, 5-halouracil and cytosine, and 5-propynyl.

[0030] [ka] Included are other synthetic and naturally occurring nucleobases such as uracil and cytosine and other alkynyl derivatives of pyrimidine bases, 6-azouracil, cytosine and thymine, 5-uracil (pseudouracil), 4-thiouracil, 8-halo, 8-amino, 8-thiol, 8-thioalkyl, 8-hydroxyl and other 8-substituted adenines and guanines, 5-halo, particularly 5-bromo, 5-trifluoromethyl and other 5-substituted uracils and cytosines, 7-methylguanine and 7-methyladenine, 2-F-adenine, 2-amino-adenine, 8-azaguanine and 8-azaadenine, 7-deazaguanine and 7-deazaadenine and 3-deazaguanine and 3-deazaadenine. Further modified nucleobases include phenoxazine cytidine (1H-pyrimido[5,4-b][1,4]benzoxazin-2(3H)-one), phenothiazine cytidine (1H-pyrimido[5,4-b][1,4]benzothiazin-2(3H)-one), G-clamp, tricyclic pyrimidines such as substituted phenoxazine cytidines (e.g., 9-(2-am-oelhoxy)-H-pyrimido[5,4-b][1,4]benzoxazin-2(3H)-one), carbazole cytidine (2H-pyrimido[4,5-b]indol-2-one), pyridoindole cytidine (H-pyrido[3,2,5]pyrrolo[2,3-d]pyrimidin-2-one). Modified nucleobases can also include those in which the purine or pyrimidine base is replaced with other heterocycles, such as 7-deaza-adenine, 7-deazaguanosine, 2-aminopyridine, and 2-pyridone.

[0031] "Alkyl" refers to an optionally substituted saturated straight- or branched-chain hydrocarbon radical. Examples include, but are not limited to, methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, tert-butyl, n-pentyl, and n-hexyl. "Cycloalkyl" refers to a cyclic alkyl group of 3 to 10 carbon atoms having a single ring or multiple rings, including, by way of example, adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and the like. In some embodiments, an optionally substituted alkyl is substituted with one or more halogens, e.g., F.

[0032] As used herein, "heterocycle" refers to a saturated, unsaturated, or aromatic ring system of 3 to 18 atoms containing at least one N, O, S, or P. In some embodiments, the heterocycle contains one N, O, or S. In some embodiments, the heterocycle contains two N, O, or S.

[0033] As used herein, the term "protecting group" refers to the chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. Examples of protecting groups include those disclosed in, for example, Greene and Wuts, Protective Groups in Organic Synthesis.

[0034] The term "activating group" includes moieties that increase the ability of a group to form a covalent bond with another molecule. Activating groups include phosphite-triester, phosphotriester, H-phosphonate, or preferably, phosphoramidite groups on at least one of the oxygen atoms of the sugar moiety. Preferably, the activating group is on the C-3' or C-5' oxygen of a nucleic acid monomer. Typically, for synthesizing a probe in the 3'→5' direction, the activating group is on the C-3' oxygen of a nucleic acid monomer, and the oligonucleotide is attached to the support via its 3' end. For synthesizing a probe in the 5'→3' ("reverse") direction, the activating group is on the C-5' oxygen of a nucleic acid monomer, and the oligonucleotide is attached to the support via its 5' end.

[0035] To assist the reader of this application, the description of the specification is divided into various paragraphs or sections or directed to various embodiments of this application. These separations should not be considered as separating a paragraph or section or embodiment entity from another paragraph or section or embodiment entity. To the contrary, those skilled in the art will understand that the present description has broad applicability and encompasses all combinations of the various sections, paragraphs, and sentences that may be contemplated. The discussion of any embodiment is intended to be merely illustrative and is not intended to suggest that the scope of the present disclosure, including the claims, is limited to these examples.

[0036] Compounds of the Disclosure In a general aspect, the present disclosure provides a compound of formula (Ia) or (Ib):

[0037] [ka] A compound represented by the formula: In the formula, X is a 3- to 5-membered cycloalkyl, —CHCH—, a 3- to 5-membered heterocycle, or —CHR 3 CHR 3 -, Y is selected from O or NR', R' is a counterion, H, or a protecting group, Z is selected from H, a counterion, an activating group, and an oligonucleotide, A and the connecting dashed line are optional, and if present, A is selected from O, S, and CR 4 R 4 B is a nucleobase; each R is independently selected from an oligonucleotide, a counterion, H, and a protecting group, e.g., C1-C5 alkyl and POM or C1-C5 alkyl; and each R 1 and R 2 is independently selected from H, F, OH, and optionally substituted O-alkyl, or R 1 and R 2 forms an optionally substituted oxetine, and each R 3 is independently selected from C1-C3 alkyl, and each R 4are independently selected from H, F, and C1-C5 alkyl, with the proviso that when A is O, X is not -CHCH-, and when X is cyclopropyl, at least one of A or Y is not O. In some embodiments, when A is present, X is selected from 3- to 5-membered cycloalkyl, -CHCH-, 3- to 5-membered heterocycle, and -CHR 3 CHR 3 - selected from R 1 and R 2 are not H, respectively.

[0038] In some embodiments, the compounds of Formula (Ia) and (Ib) are

[0039] [ka] It is expressed as:

[0040] In some embodiments, the compounds of Formula (Ia) and (Ib) are

[0041] [ka] It is expressed as:

[0042] In some embodiments, the compound of Formula (Ia) is

[0043] [ka] It is expressed as:

[0044] In some embodiments, X is cyclobutyl. In some embodiments, cyclobutyl is

[0045] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. In some embodiments, X is -CHR 3 CHR 3 - and R3 In some embodiments, X is

[0046] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. In some embodiments, X is selected from the structure:

[0047] [ka] wherein the curved line contains one or more heteroatoms (e.g., N, O, or S). In some embodiments, X is

[0048] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. In some embodiments, Y is O. In some embodiments, Y is O and X is not cyclopropyl.

[0049] In some embodiments, Z is an activating group. In some embodiments, Z is a phosphoramidite or functionally similar moiety. In some embodiments, the activating group is

[0050] [ka] where the dashed lines represent the A connection points to adjacent atoms.

[0051] In some embodiments, Z is an oligonucleotide. In some embodiments, the oligonucleotide is the antisense strand of an RNA, preferably the antisense strand of an siRNA. In some embodiments, the 5' end of the oligonucleotide is linked to Y.

[0052] In some embodiments, A is O. In some embodiments, A is O and X is not cyclopropyl. In some embodiments, A is CH or CHF.

[0053] In some embodiments, R 1 and R 2 is independently selected from H, F, OH, and optionally substituted O-alkyl, with the proviso that X is selected from 3- to 5-membered cycloalkyl, —CHCH—, 3- to 5-membered heterocycle, and —CHR 3 CHR 3 - R when selected from 1 and R 2 are not H or R 1 and R 2 forms an optionally substituted oxetine. In some embodiments, substituted O-alkyl includes -OMe, -OEt, -CH2CHOCH3 (or MOE), -CF2CHOCH3, -CH2CF2OCH3, -CH2CF2OCF3, -CF2CF2OCH3, -CH2CF2OCF3, -CF2CH2OCF3, -CF2CF2OCF3, -CHFCH2OCH3, -CHFCHFOCH3, -CHFCH2OCFH2, -CHFCH2OCHF2, and -CH2CHFOCH3, and the like.

[0054] In some embodiments, B is uracil. 1 is H and R 2 is OMe, OEt, MOE, or F. In some embodiments, R is a protecting group, e.g., POM, C1-C5 alkyl (e.g., Et), and Z is an activating group. In some embodiments, R is H and Z is an oligonucleotide.

[0055] In some embodiments, the compound is

[0056] [Table 2] or a compound of the table wherein the nucleobase is thymine or cytosine.

[0057] In some embodiments, R 2 is selected from H, F, OH, and optionally substituted O-alkyl, such as OMe, OEt, MOE, etc. In some embodiments, R 2 is -OMe. In some embodiments, each R is independently selected from an oligonucleotide, a counterion, H, and a protecting group, e.g., POM or C1-C5 alkyl. In some embodiments, R is a protecting group, e.g., POM or C1-C5 alkyl (e.g., Et), and Z is an activating group, e.g., a phosphoramidite or functionally similar moiety. In some embodiments, the activating group is

[0058] [ka] In some embodiments, R is H and Z is an oligonucleotide. [Example]

[0059] The following examples are offered to illustrate, but not limit, the invention of this disclosure. Those skilled in the art will recognize that the following procedures can be modified using methods known to those skilled in the art.

[0060] Glossary The following abbreviations are used herein: m = 2'-O-methyl modification f=2'-fluoro modification VP = vinyl phosphonate (invabasic) = inverse base ps = phosphorothioate TEG-Chol = cholesterol-triethylene glycol ecc); cc = carbocyclic; e refers to the geometric isomer of vinyl phosphonate VP(ecc)mU = carbocyclic mU e-vinylphosphonate DMP(RS) = R,S-dimethylphosphonate DMP(SR) = S,R-dimethylphosphonate DMP(RR) = R,R-dimethylphosphonate DMP(SS) = S,S-dimethylphosphonate P(ccb) = cis-cyclobutylphosphonate P(tcb) = trans-cyclobutylphosphonate (UNAA) should be equal to (UNA-A). (UNA-A) = Unlocked Adenosine Nucleic Acid (J15AdaC)=J2-C15AdaC=2'-O-[15-(adamantyl-1)pentadecyl]cytidine.

[0061] Example 1: Synthesis of dimethylphosphonate Scheme 1. Synthesis of dimethylphosphonate

[0062] [ka]

[0063] Scheme 2. Synthesis of cyclobutylphosphonate

[0064] [ka]

[0065] Example 2: Synthesis of phosphonates Example 2-1

[0066] [ka]

[0067] To a solution of potassium tert-butoxide (65.5 g, 583.8 mmol, 3.0 equiv.) in tert-butyl methyl ether (1300 mL) under an inert atmosphere of argon, sec-butyllithium (450 mL, 583.8 mmol, 3.0 equiv.) was added dropwise and stirred at −78° C. for 2.5 hours. To the resulting solution, lithium bromide (101.5 g, 1167.5 mmol, 6.0 equiv.) in tetrahydrofuran (1000 mL) was added dropwise with stirring at −78° C. The resulting solution was stirred at −15° C. for 30 minutes. The resulting solution was cooled to −78° C. To the resulting solution, copper(I) bromide-dimethyl sulfide (60 g, 291.9 mmol, 1.5 equiv.) in 6-O-(triisopropylsilyl)-d-galactal cyclic carbonate (420 mL) was added at −78°C. The resulting solution was stirred at −78°C for 1 hour. To the resulting solution, (3aR,6aR)-2,2-dimethyl-3a,6a-dihydro-4H-cyclopenta[d][1,3]dioxol-4-one (30 g, 194.6 mmol, 1.0 equiv.) in tetrahydrofuran (300 mL) was added at −78°C. The resulting solution was stirred at −30°C for 30 minutes. The reaction mixture was diluted with 2000 mL of tert-butyl methyl ether. The reaction mixture was quenched by adding 100 mL of acetic acid and methanol (v / v=1:1). The organic layer was washed with 3 x 3000 mL of a mixed aqueous ammonium chloride and ammonia solution (pH = 9). The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was applied to a silica gel column with petroleum ether / ethyl acetate (100:1 to 50:1). 35 g (74% yield) of 21 was obtained as a white solid. MS m / z [M+NH4 + ] + (ESI):260.30. 1H NMR(300MHz,DMSO-d6)δ 4.60(d,J=5.4Hz,1H),4.11(d,J=5.4,1.1Hz,1H),3.49(dd,J=8.7,2.7Hz,1H),3.35-3.29(m,1H),2.61 (dd,J=17.7,8.9Hz,1H),2.49-2.42(m,1H),1.95-1.84(m,1H),1.33(s,3H),1.27(s,3H),1.06(s,9H).

[0068] To a solution of 21 (20 g, 123.96 mmol, 1.0 equiv.) and cerium(III) chloride heptahydrate (46.172 g, 123.96 mmol, 1.0 equiv.) in methanol (180 mL) was slowly added borohydride (7.034 g, 185.94 mmol, 1.5 equiv.) at 0 °C under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 4 h. The reaction mixture was quenched by adding water. The resulting solution was extracted with 300 mL of ethyl acetate. The organic layers were combined and washed with 300 mL of brine. The organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The crude product was applied to a silica gel column with petroleum ether / ethyl acetate (50:1 to 20:1). 18 g (89% yield) of 21 was obtained as a pale yellow liquid.

[0069] To a solution of pyrimidine-2,4(1H,3H)-dione (100 g, 892.85 mmol, 1.0 equiv.) in 840 mL of acetonitrile and 160 mL of pyridine under an inert atmosphere of argon, benzoyl chloride (114.05 mL, 982.14 mmol, 1.1 equiv.) was added dropwise at 0 °C. The resulting solution was stirred at room temperature for 5 h. The reaction mixture was quenched with 200 mL of 1 N hydrochloric acid, diluted with 500 mL of dichloromethane, and washed with 3 x 200 mL of saturated aqueous sodium chloride. The organic layers were combined, dried over anhydrous sodium sulfate, and concentrated under vacuum. The residue was applied to a silica gel column with petroleum ether / ethyl acetate (10:1 to 1:1). 60 g (31% yield) of 19 was obtained as a white solid.

[0070] To a solution of 19 (60 g, 277.78 mmol, 1.0 equiv.) and 1,8-diazabicyclo[5.4.0]undec-7-ene (48 mL) in acetonitrile (600 mL) was added benzyl chloromethyl ether (52 g, 333.33 mmol, 1.2 equiv.) under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 2 h. The reaction was then concentrated in vacuo. The residue was extracted with ethyl acetate (250 mL) and washed with 1 × 200 mL of water and 1 × 200 mL of saturated aqueous sodium chloride. The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was dissolved in 600 mL of sodium methoxide (2 M sodium methoxide in methanol) and stirred at room temperature for 1 h under an inert atmosphere of argon. The reaction mixture was evaporated to dryness. The residue was applied to a silica gel column with petroleum ether / ethyl acetate (2:1 to 1:3). 55 g (85% yield) of 20 was obtained as a white solid. MS m / z[MH] - (ESI):231.00.

[0071] To a solution of 22 (28.5 g, 116.8 mmol, 1.0 equiv.), 20 (40.6 g, 175.2 mmol, 1.5 equiv.), and triphenylphosphine (76.6 g, 292.0 mmol, 2.5 equiv.) in tetrahydrofuran (1000 mL) was added diethyl azodicarboxylate (50.85 g, 292.0 mmol, 2.5 equiv.) slowly dropwise at −78°C under an inert atmosphere of argon. The resulting solution was stirred at −78°C for 1 h, then slowly warmed to room temperature and stirred for 16 h. The resulting mixture was concentrated in vacuo. The residue was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 20 min), UV 254 nm. The fraction was diluted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. Obtained 36.5 g (68% yield) of 23 as a yellow oil. MS m / z [M+H] + (ESI):459.30. 1H NMR(300MHz,chloroform-d)δ 7.32(t,J=3.3Hz,5H),7.20(d,J=7.9Hz,1H),5.71(d,J=7.8Hz,1H),5.39-5.15(m,3H),5.03(dt,J=6.8,3.5Hz,1H),4.61(d,J=3.2Hz,2H),4. 52(t,J=6.6Hz,1H),3.62(dd,J=8.7,4.6Hz,1H),3.37-3.25(m,J=8.3,5.9Hz,1H),2.33-2.03(m,3H),1.52(s,3H),1.28(s,3H),1.17(s,9H).

[0072] A solution of 23 (35 g, 76.4 mmol, 1.0 equiv) in ethyl acetate (350 mL) was heated under an inert atmosphere of hydrogen at room temperature on 10% Pd / C (w t / w t HCl (10%, 3.5 g) and trifluoroacetic acid (35 mL) were added sequentially. The resulting solution was stirred at room temperature for 4 hours. The solution was filtered and concentrated under reduced pressure. The residue was dissolved in 350 mL of 1:1 trifluoroacetic acid / water at room temperature. The resulting solution was stirred at 50°C for 2 hours under an inert atmosphere of argon. The solution was concentrated under reduced pressure. The residue was dissolved in a 1N ammonium hydroxide solution in methanol (200 mL). The resulting mixture was concentrated under vacuum. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (0% acetonitrile up to 30% in 15 minutes), UV 254 nm. The fractions were concentrated under reduced pressure. 15.7 g (85% yield) of -5 was obtained as a pale yellow oil. MS m / z [M+Na] + (ESI):265.00.

[0073] To a solution of 5 (17 g, 70.24 mmol, 1.0 equiv.) in N,N-dimethylformamide (170 mL) under an inert atmosphere of argon, diphenyl carbonate (22.57 g, 105.37 mmol, 1.5 equiv.) and sodium bicarbonate (590.38 mg, 7.02 mmol, 0.1 equiv.) were added sequentially. The reaction mixture was heated at 150 °C for 3 h until the solution turned dark red. The reaction mixture was cooled to room temperature and slowly poured into 3000 mL of diethyl ether with stirring. The precipitate was collected by filtration, redissolved in methanol, decolorized with charcoal, and filtered. The filtrate was concentrated in vacuo to give 10.3 g (73% yield) of 6 as a yellow solid. MS m / z [M−H] - (ESI):223.00.

[0074] To a solution of 6 (14.7 g, 65.62 mmol, 1.0 equiv.) in methanol (150 mL), trimethyl borate (13.6 g, 131.25 mmol, 2.0 equiv.), trimethoxymethane (6.96 g, 65.6 mmol, 1.0 equiv.), and sodium bicarbonate (1.1 g, 13.1 mmol, 0.2 equiv.) were added in that order. The reaction mixture was stirred at 150 °C for 16 h in a sealed tube. The reaction mixture was allowed to cool to room temperature and concentrated under reduced pressure. The residue was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (0% acetonitrile up to 40% in 20 min), UV 254 nm. Fractions were concentrated under reduced pressure. 7.7 g (45% yield) of 7 was obtained as a pale yellow oil. MS m / z [M−H] - (ESI):255.00.

[0075] To a solution of 7 (5 g, 19.53 mmol, 1.0 equiv.) in pyridine (50 mL) was added 4,4'-dimethoxytrityl chloride (6.94 g, 20.5 mmol, 1.05 equiv.) at 0 °C under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 2 h. The reaction mixture was quenched with 10 mL of methanol, diluted with 200 mL of dichloromethane, and washed with 2 x 150 mL of saturated aqueous sodium bicarbonate and 2 x 150 mL of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 20 min), UV 254 nm. Fractions were concentrated under reduced pressure. 8.4 g (77% yield) of 31 was obtained as a pale yellow solid. MS m / z [M−H] - (ESI):557.10. 1 H NMR(300MHz,DMSO-d6)δ 11.13(s,1H),7.45-7.35(m,3H),7.35-7.18(m,7H),6.93-6.84(m,4H) ,5.57(d,J=7.5Hz,1H),5.10-4.97(m,1H),4.37(d,J=7.3Hz,1H),4.14- 3.99(m,1H),3.90(t,1H),3.74(s,6H),2.89(t,J=7.9Hz,1H),3.23-3. 15(m,3H),1.96-1.69(m,2H),1.35-1.08(m,1H),0.83(t,J=7.3Hz,1H).

[0076] To a solution of 31 (8.4 g, 15.05 mmol, 1.0 equiv.) in N,N-dimethylformamide (85 mL) was added imidazole (2.55 g, 37.59 mmol, 2.5 equiv.) and tert-butyldimethylsilyl chloride (5.66 g, 37.59 mmol, 2.5 equiv.) sequentially at room temperature under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 2 h. The reaction mixture was diluted with 500 mL of dichloromethane and washed with 2 × 200 mL of saturated aqueous sodium bicarbonate and 1 × 200 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 20 min), UV 254 nm. Fractions were concentrated under reduced pressure. Obtained 8.6 g (81% yield) of 32 as a pale yellow oil. MS m / z [M−H] - (ESI):671.30.

[0077] To a solution of 32 (10.0 g, 14.88 mmol, 1.0 equiv.) dissolved in 100 mL of 6% dichloroacetic acid in dichloromethane was added triethylsilane (5.2 g, 44.64 mmol, 3.0 equiv.) under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 1 h. The reaction mixture was diluted with 200 mL of dichloromethane and washed with 2 × 200 mL of saturated aqueous sodium bicarbonate, 1 × 100 mL of water, and 1 × 200 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 20 min), UV 254 nm. Fractions were concentrated under reduced pressure to obtain 4.2 g (76%) of 31 as a white solid. MS m / z [M−H] - (ESI):369.15. 1H NMR(300MHz,DMSO-d6)δ 11.09(d,J=5.8Hz,1H),7.42(dd,J=7.6,5.8Hz,1H),5.57(dd,J=7.6,1.5Hz,1H), 5.05(td,J=9.7,5.5Hz,1H),4.52(t,J=5.2Hz,1H),4.26(dd,J=6.7,5.4Hz,1H),4 .02(t,J=5.4Hz,1H),3.49-3.59(m,J=10.6,5.3Hz,1H),3.33-3.27(m,1H),3.17( s, 3H), 1.90-2.03 (m, J=7.5Hz, 1H), 1.86-1.56 (m, 2H), 0.88 (s, 9H), 0.06 (d, 6H).

[0078] To a solution of 9 (2.5 g, 6.74 mmol, 1.0 equiv.) in 25 mL of dichloromethane was added Dess-Martin periodinane (4.0 g, 10.12 mmol, 1.5 equiv.) at 0 °C under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 1 h. The reaction mixture was diluted with 300 mL of dichloromethane and washed with 1 × 200 mL of saturated aqueous sodium thiosulfate, 1 × 200 mL of saturated aqueous sodium bicarbonate, 2 × 100 mL of water, and 1 × 200 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain 2.1 g (84%) of 10 as a white solid. MS m / z [M−H] - (ESI): 367.05. This was used in the next step without further purification.

[0079] To a solution of tetraethyl methylenebis(phosphonate) (2.13 g, 7.41 mmol, 1.3 equiv) in anhydrous tetrahydrofuran (20 mL) was added potassium tert-butoxide (2.13 g, 5.70 mmol, 1.35 equiv) at 0 °C. The reaction mixture was stirred at 0 °C for 10 min and then warmed to room temperature for 30 min. A solution of 10 (2.10 g, 5.70 mmol, 1.0 equiv) in 20 mL of anhydrous tetrahydrofuran was then added dropwise at 0 °C. The resulting solution was stirred at 0 °C for 3 h. The reaction mixture was diluted with 200 mL of dichloromethane and washed with 2 × 200 mL of saturated aqueous sodium bicarbonate. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 20 min), UV 254 nm. The residue was diluted with an equal volume of dichloromethane. The organic layer was separated. The aqueous phase was extracted with 3 x 20 mL of dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solid was filtered. The filtrate was concentrated at 25 °C. 2 g (68%) of 12 was obtained as a pale yellow solid. MS m / z [M+H] + (ESI):503.20. 1 H NMR(300MHz,DMSO-d6)δ 11.18(s,1H),7.45(d,J=7.6Hz,1H),6.65-6.48(m,J=21.9,17.1,7.6Hz,1H),5.9 0-5.81(m,1H),5.61(d,J=7.5Hz,1H),5.06-4.95(m,1H),4.40(dd,J=9.8,5.8Hz,1 H),4.00-3.89(m,J=8.3,7.0,1.3Hz,4H),3.81(dd,J=5.9,2.6Hz,1H),3.21(s,3H ),2.75(s,1H),1.93-.73(m,2H),1.22(t,J=7.0Hz,6H),0.87(s,9H),0.03(s,6H). 31 P NMR(121MHz,DMSO-d6)δ 17.62.

[0080] 11 (2.00 g, 5.15 mmol, 1.0 equiv.) was dissolved in 20 mL of formic acid and HO (v / v=1:1) under an inert atmosphere of argon. The mixture was stirred at room temperature for 1 h. The resulting solution was concentrated under reduced pressure. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (15% acetonitrile up to 35% in 20 min), UV 254 nm. The fractions were concentrated under reduced pressure. 1.3 g (84%) of 12 was obtained as a white solid. MS m / z [M+H] + (ESI):389.25. 1 H NMR(300MHz,DMSO-d6)δ 11.17(d,1H),7.48-7.38(m,1H),6.76-6.55(m,1H),5.87-5.72(m,1H),5.60(d,1H),5.02(td,1H),4.74(d,1H),4.17 -4.07(m,1H),4.02-3.90(m,4H),3.88-3.83(m,1H),3.26(s,3H),2.75-2.58(m,1H),1.94-1.72(m,2H),1.23(td,6H). 31 P NMR(121MHz,DMSO-d6)δ 18.08.

[0081] To a solution of 12 (1.7 g, 4.38 mmol, 1.0 equiv.) in dichloromethane (170 mL), diamino)phosphinooxy)propanenitrile (1.72 g, 5.69 mmol, 1.3 equiv.) and 4,5-dicyanoimidazole (569 mg, 4.88 mmol, 1.1 equiv.) were added in sequence. The resulting solution was stirred at room temperature for 40 min. The resulting solution was diluted with 500 mL of dichloromethane and washed with 1 × 300 mL of sodium bicarbonate and 1 × 300 mL of brine, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. The residue was diluted with an equal volume of dichloromethane. The organic layer was separated. The aqueous phase was extracted with 3x50 mL of dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solid was filtered. The filtrate was concentrated at 25°C and dried under reduced pressure at 25°C for 4 hours to give the product. 1.85 g of 0 was obtained as a white solid. MS m / z [M−H] - (ESI):587.10. 1 H NMR (300 MHz, DMSO-d6) δ 11.14(s,1H),7.42(dd,J=7.6,1.1Hz,1H),6.67-6.49(m,1H),5.95-5.69(m,1 H),5.59(d,J=7.6Hz,1H),5.10-4.98(m,1H),4.53-4.29(m,1H),4.02-3.83(m, 5H),3.80-3.66(m,2H),3.63-3.47(m,2H),3.22(d,J=3.0Hz,3H),2.85(s,1H) ,2.79-2.71(m,2H),1.96-1.76(m,2H),1.24-1.17(m,6H),1.15-1.11(m,12H). 31 P NMR(121MHz,DMSO)δ 147.53,146.78,17.69,17.50.

[0082] Example 2-2

[0083] [ka]

[0084] To a solution of (3aR,5S,6R,6aR)-5-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxol-6-ol (400 g, 1.54 mol, 1.0 equiv.) in 4 L of tetrahydrofuran under an inert atmosphere of nitrogen was added sodium hydride (55.2 g, 2.31 mol, 1.5 equiv.) at 0° C. The resulting solution was stirred at 0° C. for 20 minutes. Then, 2-(bromomethyl)naphthalene (509.7 g, 2.31 mol, 1.5 equiv.) was added dropwise with stirring at 0° C. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was quenched with saturated aqueous ammonium chloride. The resulting mixture was diluted with 4 L of ethyl acetate and washed with 2×4 L of water and 2×4 L of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:5 to 1:3). 490 g (80%) of 41 was obtained as a yellow oil. MS m / z [M+Na] + (ESI):423.08.

[0085] 41 (490 g, 1.23 mol, 1.0 equiv.) was dissolved in acetic acid (80% in water, 4900 mL) under an inert atmosphere of nitrogen and stirred overnight at room temperature. The resulting mixture was concentrated under reduced pressure and diluted with 5000 mL of ethyl acetate. The resulting mixture was washed with 3 x 1500 mL of saturated aqueous sodium bicarbonate, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:5 to 1:1). 390 g (85%) of 42 was obtained as a yellow oil. MS m / z [M+Na] + (ESI):383.21.

[0086] To a mixture of 42 (195 g, 0.54 mol, 1.0 equiv.) in 2000 mL of dichloromethane, imidazole (146.8 g, 2.16 mol, 4.0 equiv.) and tert-butyldiphenylchlorosilane (156 g, 0.55 mol, 1.05 equiv.) were added sequentially at 0 °C under an inert atmosphere of argon. The reaction mixture was allowed to warm to room temperature and stirred at room temperature for 4 h. The resulting solution was diluted with 5000 mL of dichloromethane and washed with 3 × 1500 mL of water and 3 × 1500 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:10 to 1:5). 190 g (60%) of 43 was obtained as a yellow oil. MS m / z [M+Na] + (ESI):621.25. 1 H NMR(300MHz,DMSO-d6)δ 7.90-7.85(m,1H),7.79-7.71(m,3H),7.65-7.56(m,4H),7.50-7.45(m,2H),7.43-7. 33(m,5H),7.29-7.22(m,2H),5.72(d,J=3.7Hz,1H),5.06(d,J=4.8Hz,1H),4.78-4.72 (m,2H),4.57(d,J=11.9Hz,1H),4.19-4.15(m,1H),4.13-3.98(m,1H),3.87-3.94(m, 1H),3.83-3.77(m,1H),3.57(d,J=6.5Hz,1H),1.47(s,3H),1.30(s,3H),0.94(s,9H).

[0087] To a solution of oxalyl chloride (120.84 g, 0.953 mol, 1.5 equiv) in dichloromethane (2000 mL) was added dimethyl sulfoxide (78.19 g, 0.95 mol, 3.0 equiv) dropwise with stirring at −78°C. The resulting solution was stirred at −78°C for 30 min, and then a solution of 43 (120 g, 158.86 mmol, 1.0 equiv) in dichloromethane (500 mL) was added dropwise with stirring at −78°C. The resulting solution was reacted with stirring for an additional 1.5 h at −78°C. Triethylamine (72.24 g, 714.75 mmol, 4.5 equiv) was then added dropwise with stirring at −78°C. The resulting solution was reacted with stirring for an additional 2 h at −78°C. The resulting solution was diluted with 500 mL of dichloromethane. The resulting mixture was washed with 1 x 500 mL of saturated aqueous sodium bicarbonate and 1 x 500 mL of saturated aqueous sodium chloride, respectively. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:10 to 1:6). 80 g (85%) of 44 was obtained as a yellow oil. MS m / z [M+Na] + (ESI):619.57.

[0088] To a solution of methyltriphenylphosphonium bromide (96.2 g, 0.269 mol, 2.0 equiv.) in tetrahydrofuran (500 mL) was added sodium hydride (6.5 g, 0.269 mol, 2.0 equiv.) under a nitrogen inert atmosphere. The resulting solution was stirred at room temperature for 30 minutes. A solution of 44 (80 g, 134.7 mmol, 1.00 equiv.) in tetrahydrofuran (500 mL) was added. The resulting solution was stirred at room temperature for an additional 3 hours. The reaction was then quenched by adding saturated aqueous ammonium chloride. The resulting solution was extracted with 4000 mL of ethyl acetate, and the organic layers were combined. The resulting mixture was washed with water and saturated aqueous sodium chloride. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:20 to 1:5). 63 g (80%) of 45 was obtained as a yellow oil. MS m / z [M+Na] + (ESI):617.60.

[0089] To a solution of 45 (125 g, 210.4 mmol, 1.0 equiv.) in tetrahydrofuran (1250 mL) was added borane-methyl sulfide complex (10 M, 42.1 mL, 2.0 equiv.) at 0 °C. The resulting solution was stirred at room temperature for 2 h. Sodium hydroxide (2N in water, 630 mL, 6.0 equiv.) was then added at room temperature, and hydrogen peroxide (30%, 143.1 g, 6.0 equiv.) was added dropwise with stirring at room temperature. The resulting solution was allowed to react with stirring for another 2 h at room temperature. The resulting solution was extracted with 2 × 2000 mL of dichloromethane, and the organic layers were combined. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:20 to 1:5). 73 g (56%) of 46 was obtained as a yellow oil. MS m / z [M+Na] + (ESI):635.62.

[0090] To a solution of triethylamine trihydrofluoride (381.6 g, 2.37 mol, 10.0 equiv.) in 730 mL of dry tetrahydrofuran was added triethylamine (391.5 g, 2.37 mol, 10.0 equiv.) at room temperature under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 10 minutes. A solution of 46 (145 g, 236.54 mmol, 1.0 equiv.) in 730 mL of dry tetrahydrofuran was added to the resulting solution. The reaction mixture was stirred at room temperature for 12 hours, diluted with 3000 mL of dichloromethane, and washed with 2 × 1000 mL of saturated aqueous sodium bicarbonate and 2 × 1000 mL of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.1% FA) and acetonitrile (10% acetonitrile up to 100% in 12 min), UV 254 nm. The fractions were diluted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 70 g (80%) of 47 as a pale yellow oil. MS m / z [M+Na] +(ESI):397.15.1H NMR(300MHz,chloroform-d)δ 7.93-7.80(m,4H),7.57-7.46(m,3H),5.77(d,J=3.9Hz,1H),5.00(d,J=11.4Hz,1H),4.77-4.64( m,2H),4.23(m,1H),3.92-3.73(m,5H),2.29(s,3H),2.03-1.87(m,1H),1.64(s,3H),1.40(s,3H).

[0091] To a solution of 47 (70 g, 187.17 mmol, 1.0 equiv.) in 700 mL of dry pyridine was added 4-methylbenzenesulfonyl chloride (107.12 g, 561.51 mmol, 3.0 equiv.) at 0 °C under an inert atmosphere of nitrogen. The reaction mixture was then stirred at room temperature for 12 h. The reaction was quenched by adding water and concentrated under reduced pressure. The reaction mixture was diluted with 3000 mL of dichloromethane and washed with 1 × 1000 mL of saturated aqueous sodium bicarbonate and 2 × 1000 mL of saturated sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate. The solid was filtered and concentrated under reduced pressure. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (10% acetonitrile up to 100% in 15 min, held at 100% for 5 min); detector, UV 254 nm. 90 g (70%) of 48 was obtained as a pale yellow solid. [M+Na+] + (ESI):705.81

[0092] To a solution of diethyl ((phenylthio)methyl)phosphonate (22.62 g, 87.00 mmol, 2.00 equiv.) in 150 mL of dry tetrahydrofuran was added butyllithium (2 M, 43.50 mL, 2.00 equiv.) dropwise with stirring at −78°C under an inert atmosphere of nitrogen. The resulting solution was stirred at −30°C for 2 hours. A solution of 48 (30 g, 43.99 mmol, 1.00 equiv.) in 150 mL of tetrahydrofuran was added dropwise with stirring at −78°C. The resulting solution was stirred at room temperature for 12 hours. The resulting solution was extracted with ethyl acetate, and the organic layers were combined. The organic layers were washed with 1×500 mL of water and 2×500 mL of saturated sodium chloride, respectively. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 12.5 g (50%) of 201 was obtained as a pale yellow solid. [M+H+] + (ESI):599.66

[0093] To a solution of 201 (15 g, 25.08 mmol, 1.0 equiv.) in 300 mL of toluene was added 2,2'-azobis(2-methylpropionitrile) (3.29 g, 20.07 mmol, 0.4 equiv.) and tributylstannane (14.6 g, 50.16 mmol, 2.0 equiv.) at room temperature under an inert atmosphere of nitrogen. The resulting solution was stirred at 110 °C for 1 h. The resulting mixture was concentrated under reduced pressure. The crude product was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 8.5 g (65%) of 91 was obtained as a pale yellow solid. [M+H+] +(ESI):491.15.1H NMR(400MHz,DMSO-d6)δ 7.96-7.82(m,4H),7.57-7.43(m,3H),5.80-5.71(m,1H),4.85-4.72(m,2H),4.64(d,J=12.2Hz,1H),4.02-3.78(m,5H) ),3.51-3.44(m,1H),2.65-2.58(m,2H),2.21-1.85(m,4H),1.48(d,J=5.0Hz,3H),1.31(d,J=3.1Hz,3H),1.19(m,6H). 31P NMR (162MHz, DMSO) δ 33.08,30.36.

[0094] To a solution of 91 (17 g, 34.69 mmol, 1.0 equiv.) in 170 mL of acetic acid under an inert atmosphere of nitrogen, acetyl acetate (35.4 g, 346.94 mmol, 10.0 equiv.) and sulfuric acid (679.9 mg, 6.94 mmol, 0.2 equiv.) were added. The resulting solution was stirred at room temperature for 2 h. The reaction was then quenched by adding ice water. The resulting solution was extracted with ethyl acetate. The resulting solution was washed with water and saturated aqueous sodium chloride. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (20% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 14 g (75%) of 82 was obtained as a pale yellow solid. MS m / z [M+H] + (ESI):535.72.

[0095] To a solution of uracil (5.87 g, 52.43 mmol, 2.0 equiv.) in 140 mL of acetonitrile was added N,O-bis(trimethylsilyl)acetamide (23.95 g, 117.98 mmol, 4.5 equiv.) at room temperature under an inert atmosphere of nitrogen. The resulting solution was stirred at 60 °C for 0.5 h. To this was added 82 (14 g, 26.22 mmol, 1.00 equiv.) at 0 °C, followed by dropwise addition of perchlorostannane (8.86 g, 34.08 mmol, 1.3 equiv.) with stirring at 0 °C. The resulting solution was allowed to react at 60 °C for an additional 1 h with stirring. The reaction mixture was cooled to 0 °C and quenched by the addition of 100 mL of saturated aqueous sodium bicarbonate. The resulting solution was extracted with 2 × 300 mL of ethyl acetate, and the organic layers were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (45% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 9 g (60%) of 83 was obtained as a white solid. MS m / z [M+H] + (ESI):587.10.1H NMR(300MHz,DMSO-d6)δ 11.43(s,1H),7.93(d,J=8.7Hz,3H),7.84(s,1H),7.68(d,J=13.4Hz,1H),7.54(d,J=9. 3Hz,2H),7.47(d,J=8.5Hz,1H),5.79(dd,J=12.3,3.8Hz,1H),5.68(d,J=8.0Hz,1H),5. 49-5.42(m,1H),4.68(d,J=2.7Hz,2H),4.11(t,J=6.3Hz,1H),3.98-3.90(m,5H),2.78- 2.56(m,2H),2.10(s,4H),2.04-1.98(m,1H),1.24(d,J=7.0Hz,2H),1.21-1.14(m,6H). 31P NMR (121MHz, DMSO) δ 32.76, 30.94, 30.15, 30.14.

[0096] To a solution of 83 (9 g, 15.36 mmol, 1.0 equiv.) in 90 mL of ethanol was added sodium methanolate (1.24 g, 23.04 mmol, 1.5 equiv.) at 0° C. under an inert atmosphere of nitrogen. The resulting solution was stirred at room temperature for 2 h. The mixture was then adjusted to pH=7 with Amberlite IR-120 (H+). The resulting mixture was filtered, and the filter cake was washed with 3×50 mL of ethanol. The filtrate was concentrated under reduced pressure. 9 g of this crude product was used in the next step without further purification. MS m / z [M+H] + (ESI):549.32.

[0097] To a solution of 84 (15.36 mmol, 1.0 equiv) in 70 mL of tetrahydrofuran was added sodium hydride (737.28 mg, 30.72 mmol, 2.0 equiv) at 0 °C under an inert atmosphere of nitrogen. The mixture was stirred at 0 °C for 30 minutes. A solution of methyl iodide (4.33 g, 30.72 mmol, 2.0 equiv) in 20 mL of tetrahydrofuran was added dropwise at 0 °C. The resulting solution was stirred at room temperature for 2 hours. The reaction was quenched with 50 mL of water. The resulting solution was extracted with 200 mL of ethyl acetate, and the organic phases were combined. The organic phase was washed with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (20% acetonitrile up to 100% in 25 min, held at 100% for 5 min); detector, UV 254 nm. 5 g (60% over two steps) of 416 was obtained as a white solid. MS m / z [M+H] + (ESI):559.41.

[0098] To a solution of 416 (6.0 g, 14.33 mmol, 1.0 equiv.) in 72 mL of dichloromethane and 8 mL of water was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (4.6 g, 20.06 mmol, 1.4 equiv.) at room temperature under an inert atmosphere of nitrogen. The resulting solution was stirred at room temperature for 1 h. The reaction mixture was diluted with 40 mL of water and extracted with 200 mL of dichloromethane. The aqueous phase was concentrated under reduced pressure. The crude product was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (5% acetonitrile up to 50% in 15 min, held at 100% for 5 min); detector, UV 254 nm. 3 g (60%) of the mixture was obtained as a white solid and separated by SFC. 1.5 g of 417 was obtained as a white solid. MS m / z[M+H] + (ESI):419.00. 31 P NMR (162 MHz, DMSO) δ 30.27. 1 H NMR(400MHz,DMSO-d6)δ 11.39(d,J=2.3Hz,1H),7.60(d,J=8.0Hz,1H),5.77-5.74(m,1H),5.66(dd,J=8.1,2.2Hz,1H),5.17(s,1H)4.07-3.89(m,4H) ),3.89-3.79(m,2H),3.68(dd,J=7.4,5.1Hz,1H),3.34(s,3H),2.69-2.61(m,2H),2.15-1.97(m,4H),1.20(t,J=7.1Hz,6H).

[0099] Obtained 1.2 g of 417S (used in 100) as a white solid. MS m / z [M+H] + (ESI):419.00. 31 P NMR (162 MHz, DMSO) δ 32.80 1H NMR(400MHz,DMSO-d6)δ 11.39(d,J=2.2Hz,1H),7.57(d,J=8.1Hz,1H),5.79-5.76(m,1H),5.67(dd,J=8.0,2.2Hz,1H),5.17(s,1H),4.07-3.9 0(m,4H),3.90-3.77(m,3H),3.34(s,3H),2.63(q,J=8.8,7.4Hz,2H),2.26-2.02(m,4H),1.22(td,J=7.1,0.8Hz,6H).

[0100] To a solution of 417 (1.5 g, 3.6 mmol, 1.0 equiv.) in 15 mL of dichloromethane, 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite (1.41 g, 4.7 mmol, 1.3 equiv.) and 4,5-dicyanoimidazole (467.3 mg, 3.9 mmol, 1.1 equiv.) were added sequentially at room temperature under an inert argon atmosphere. The reaction mixture was stirred at room temperature for 1 hour. The reaction solution was diluted with 100 mL of dichloromethane and washed with 1 × 20 mL of saturated aqueous sodium bicarbonate and 1 × 20 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure until no residual solvent remained. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (20% acetonitrile up to 100% in 10 min, held at 100% acetonitrile for 5 min). The organic layer was separated. The aqueous phase was extracted with 3 x 50 mL of dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solid was filtered. The filtrate was concentrated at 25 °C and dried under vacuum at 25 °C for 6 h to give the product. 1.38 g (64%) of 2-0 was obtained as a white solid. MS m / z [MH] - (ESI):617.15. 1H NMR(300MHz,chloroform-d)δ 9.24(s,1H),7.40-7.36(m,1H),5.82-5.72(m,2H),4.14-4.03(m,5H),4.01-3.81(m,3H),3.76-3.5 6(m,3H),3.51(m,3H),2.80-2.59(m,4H),2.33-2.22(m,4H),1.33-1.28(m,6H),1.22-1.17(m,12H). 31 P NMR(121MHz, CDCl3)δ 149.84,149.66,29.89,29.55.

[0101] [ka]

[0102] To a solution of 417 (1.2 g, 2.9 mmol, 1.0 equiv.) in 20 mL of dichloromethane, 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite (1.1 g, 3.8 mmol, 1.3 equiv.) and 4,5-dicyanoimidazole (376.4 mg, 3.2 mmol, 1.1 equiv.) were added sequentially at room temperature under an inert argon atmosphere. The reaction mixture was stirred at room temperature for 1 hour. The reaction solution was diluted with 20 mL of dichloromethane and washed with saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure until no residual solvent remained. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (20% acetonitrile up to 100% in 10 min, held at 100% acetonitrile for 5 min). The organic layer was separated. The aqueous phase was extracted with 3 x 50 mL of dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solid was filtered. The filtrate was concentrated at 25 °C and dried under vacuum at 25 °C for 4 h to give the product. 990.9 mg (70%) of 2-100 was obtained as a white solid. MS m / z [MH] - (ESI):617.25. 1H NMR(300MHz,chloroform-d)δ 9.28(s,1H),7.30-7.23(m,1H),5.85(dd,J=7.7,3.2Hz,1H),5.77(dd,J=8.1,1.2Hz,1H),4.19-4.05(m,5H),4.02-3.55(m,6) H),3.51(d,J=11.7Hz,3H),2.85-2.71(m,1H),2.69-2.58(m,3H),2.56-2.18(m,4H),1.37-1.27(m,6H),1.25-1.11(m,12H). 31 P NMR(121MHz, CDCl3)δ 149.70,149.69,32.96,32.65.

[0103] Example 2-3

[0104] [ka]

[0105] To a solution of (3R,4S,5R)-5-(hydroxymethyl)tetrahydrofuran-2,3,4-triol (600 g, 3.997 mol, 1.0 equiv.) in 6 L of methanol under an inert atmosphere of argon was slowly added sulfuric acid (39.19 g, 0.4 mol, 0.1 equiv.) at 0 °C. The reaction mixture was allowed to warm to room temperature and stirred overnight. The mixture was adjusted to pH 7 with sodium bicarbonate, then filtered and concentrated under reduced pressure to give 21 (520 g, crude) as a yellow oil. MS m / z [M+H] + (ESI): 165.07. The crude product was used in the next step without further purification.

[0106] To a solution of 21 (260 g, 1.584 mol, 1.0 equiv.) in 2.6 L of pyridine was added 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane (549.5 g, 1.742 mol, 1.1 equiv.) at 0 °C under an inert atmosphere of argon. The mixture was stirred at room temperature for 1 h. The resulting solution was extracted with 3 × 4 L of ethyl acetate, and the organic layers were combined. The organic layers were washed with 2 × 500 mL of water and 2 × 4 L of saturated sodium chloride, respectively. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was dissolved in 100 mL of ethyl acetate and evaporated to dryness. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:5 to 1:3). 195 g (33%) of 22 was obtained as a yellow oil. MS m / z [M+H] + (ESI):407.23.

[0107] To a mixed solution of 22 (195 g, 0.48 mol, 1.0 equiv.) in 2 L of 1,3-dimethyl-2-imidazolidinone and 1 L of iodomethane under an inert atmosphere of argon, sodium hydride (23.1 g, 0.959 mol, 2.0 equiv.) was added. The resulting solution was stirred at room temperature for 40 min. The resulting solution was diluted with dichloromethane and washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, ethyl acetate / petroleum ether = 1:5 to 1:1) to give 23 (390 g, crude) as a yellow oil. MS m / z [M+H] + (ESI): 421.25. H NMR (400 MHz, chloroform-d) δ 4.77 (s, 1H), 4.50 (m, 1H), 4.01 (m, 2H), 3.94-3.84 (m, 1H), 3.61 (d, J = 4.3 Hz, 1H), 3.59 (s, 3H), 3.34 (s, 3H), 1.15-1.02 (m, 28H). The crude product was used in the next step without further purification.

[0108] To a solution of triethylamine trihydrofluoride (3 kg, 18.541 mol, 10.0 equiv.) in 5 L of dry tetrahydrofuran was added triethylamine (3.7 kg, 37.082 mol, 20.0 equiv.) at room temperature under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 10 minutes. A solution of 23 (780 g, 1.854 mol, 1.0 equiv.) in 1 L of dry tetrahydrofuran was added to the resulting solution. The reaction mixture was stirred overnight at room temperature, diluted with 3 L of dichloromethane, and washed with 2 × 1 L of saturated aqueous sodium bicarbonate and 2 × 1 L of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, ethyl acetate / petroleum ether = 1:5 to 3:1) to give 24 (280 g) as a yellow oil. MS m / z [M+H] + (ESI):179.11.

[0109] To a solution of crude 24 (140 g, 0.786 mol, 1.0 equiv.) in 1.4 L of pyridine under an inert atmosphere of argon, 4,4'-(chloro(phenyl)methylene)bis(methoxybenzene) (292.8 g, 0.865 mol, 1.1 equiv.) was added at 0 °C. The mixture was stirred at room temperature for 12 h. The resulting solution was diluted with 3000 mL of dichloromethane and washed with 2 × 1000 mL of water. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:50 to 1:1). 230 g (61%) of 25 was obtained as a yellow oil. MS m / z [M+H] + (ESI):481.23.

[0110] To a solution of 25 (460 g, 0.957 mol, 1.00 equiv.) in 4.6 L of N,N-dimethylformamide under an inert atmosphere of nitrogen, tert-butylchlorodiphenylsilane (289.4 g, 1.053 mol, 1.1 equiv.) and imidazole (162.9 g, 2.393 mol, 2.5 equiv.) were added at room temperature. The resulting solution was stirred at room temperature for 12 h. The organic layer was washed with water and extracted with 3 × 4 L of ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:20 to 1:5). 520 g (72%) of 26 was obtained as a yellow oil. MS m / z [M+H] + (ESI):719.35.

[0111] To a solution of 26 (520 g, 166.910 mmol, 1.0 equiv.) in 5.2 L of dichloromethane was added triethylsilane (500 mL) at room temperature. Trifluoroacetic acid (500 mL) was then added at 0 °C, and the resulting solution was stirred at room temperature for 2 h. The reaction was quenched by adding 5 L of saturated sodium bicarbonate and extracted with 3 × 2 L of dichloromethane. The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:10 to 5:1). The desired product fraction was concentrated under reduced pressure to give 260 g (82%) of 27 as a yellow oil. MS m / z [M+NH4] + (ESI):434.35. H NMR(400MHz,DMSO-d6)δ 7.81-7.34(m,10H),4.79(d,J=1.5Hz,1H),4.65(s,1H),4.16(m,1H),3.91(m,1H),3.44( dd,J=11.6,3.6Hz,1H),3.22(m,1H),3.19(s,3H),3.11(s,3H),3.03(m,1H),1.03(s,9H).

[0112] To a solution of oxalyl chloride (47.3 g, 372.6 mmol, 2.0 equiv.) in 1.3 L of dichloromethane was added dimethyl sulfoxide (43.7 g, 558.9 mmol, 3.0 equiv.) at −78° C. under an inert atmosphere of nitrogen. The resulting solution was stirred at −78° C. for 0.5 h, and then a solution of 27 (75 g, 186.3 mmol, 1.0 equiv.) in 750 mL of dichloromethane was added dropwise with stirring at −78° C. The resulting solution was stirred at −78° C. for 3 h. Triethylamine (84.8 g, 838.4 mmol, 4.5 equiv.) was then added dropwise with stirring at −78° C. for 0.5 h. The resulting solution was diluted with 2000 mL of dichloromethane. The resulting mixture was washed with 1×1 L of saturated aqueous sodium bicarbonate and 1×1 L of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The above process was repeated twice to obtain 120 g (crude) of 28 as a yellow oil. The crude product was used in the next step without further purification. MS m / z [M+H] + (ESI):415.21.

[0113] To a solution of 28 (120 g, 289.5 mmol, 1.0 equiv.) in 1.2 L of tetrahydrofuran was added methylmagnesium bromide (103.549 g, 868.4 mmol, 3.0 equiv.) at -78 °C under an inert atmosphere of nitrogen. The resulting solution was stirred at -78 °C for 2 h. The resulting solution was diluted with 3 L of dichloromethane and washed with 2 × 1000 mL of water. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:10 to 5:1). The desired product fraction was concentrated under reduced pressure to give 86 g (62%) of 3-1 as a yellow oil. MS m / z [M+H] + (ESI):431.25.

[0114] To a solution of oxalyl chloride (50.7 g, 399.4 mmol, 2.0 equiv.) in 860 ml of dichloromethane under an inert atmosphere of nitrogen, dimethyl sulfoxide (46.8 g, 599.12 mmol, 3.0 equiv.) was added at −78°C. The resulting solution was stirred at −78°C for 0.5 h. 3-1 (86 g, 199.7 mmol, 1.00 equiv.) was added. The resulting solution was stirred at −78°C for 3 h. Triethylamine (90.9 g, 898.7 mmol, 4.5 equiv.) was then added dropwise with stirring at −78°C. The resulting solution was stirred at −78°C for 0.5 h. The resulting solution was diluted with 1 L of dichloromethane and washed with 3 × 600 mL of water. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:50 to 3:1). The desired product fractions were concentrated under reduced pressure to give 72 g (80%) of 3-2 as a yellow oil. MS m / z [M+H] + (ESI):429.22. H NMR(300MHz,DMSO-d6)δ 7.71-7.30(m,10H),4.94(d,J=1.2Hz,1H),4.36(m,1H),4.27(d,J=6.8Hz,1H),3.12(s,3H),3.01(m,1H),1.99(d,J=4.9Hz,3H),1.01(s,9H).

[0115] A solution of 3-2 (72 g, 168.0 mmol, 1.0 equiv.) in 720 mL of N,N-dimethylformamide dimethyl acetal was stirred at 110 °C for 17 h, then diluted with 1 L of dichloromethane and washed with 2 × 600 mL of water. The resulting mixture was concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:50 to 5:1). The desired product fractions were concentrated under reduced pressure to give 60 g (70%) of 4-1 as a yellow oil. MS m / z [M+H] + (ESI):484.26.

[0116] To a solution of 4-1 (30 g, 62.026 mmol, 1.0 equiv.) in 100 mL of acetic acid and 200 mL of 1,4-dioxane was added diethylphosphonate (17.1 g, 124.1 mmol, 2.0 equiv.) and manganese triacetate dihydrate (49.9 g, 186.1 mmol, 3.0 equiv.) at room temperature under an inert nitrogen atmosphere. The resulting solution was stirred at 80 °C for 20 minutes. The resulting solution was extracted with 3 × 500 mL of ethyl acetate, and the organic layers were combined. The organic layers were washed with 2 × 200 mL of water and 2 × 200 mL of saturated sodium chloride, respectively. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The above process was repeated twice. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. This gave 38 g (52%) of 4-52 as a yellow oil. MS m / z [M+H] + (ESI):565.25.

[0117] To a solution of 4-52 (38 g, 67.3 mmol, 1.0 equiv.) in 380 mL of 1,1-dimethoxy-N,N-dimethylmethanamine was added. The resulting solution was stirred at 80 °C for 12 h. The resulting solution was diluted with 500 mL of dichloromethane and washed with 2 × 300 mL of water. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (15% acetonitrile up to 100% in 25 min, held at 100% for 5 min); detector, UV 254 nm. 27 g (62%) of 4-53 was obtained as a yellow solid. MS m / z [M+H] + (ESI):620.30.

[0118] To a solution of 4-53 (27 g, 43.56 mmol, 1.0 equiv.) in 270 mL of ethanol under an inert atmosphere of nitrogen, hydroxylamine hydrochloride (9.1 g, 130.7 mmol, 3.0 equiv.) and pyridine (34.5 g, 435.6 mmol, 10.0 equiv.) were added at room temperature. The final reaction mixture was stirred at 60 °C for 1 h. The resulting solution was diluted with 400 mL of dichloromethane and washed with 2 × 200 mL of water. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 16 g (59.2%) of 4-4 was obtained as a yellow oil. MS m / z [M−H] - (ESI):588.25.

[0119] To a solution of 4-4 (16 g, 42.395 mmol, 1.0 equiv.) in 160 mL of acetic acid and 80 mL of acetic anhydride was added sulfuric acid (133.1 mg, 1.357 mmol, 0.05 equiv.) dropwise with stirring at 0 °C. The resulting solution was stirred at room temperature for 1 h, then diluted with 300 mL of dichloromethane and washed with 2 × 100 mL of water. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (15% acetonitrile up to 100% in 25 min, held at 100% for 5 min); detector, UV 254 nm. 12 g (68%) of 4-24 was obtained as a yellow oil. MS m / z [M+H] + (ESI):618.24.

[0120] To a solution of uracil (0.544 g, 4.86 mmol, 1.5 equiv.) in 80 mL of acetonitrile was added N,O-bis(trimethylsilyl)acetamide (2.305 g, 11.3 mmol, 3.5 equiv.) at room temperature under an inert atmosphere of nitrogen. The resulting solution was stirred at 60 °C for 0.5 h. The reaction mixture was cooled to 0 °C, and 4-4 (2 g, 3.24 mmol, 1.0 equiv.) was added. Trimethylsilyl trifluoromethanesulfonate (1.44 g, 6.48 mmol, 2.0 equiv.) was then added dropwise with stirring at 0 °C. The resulting solution was reacted at 60 °C for 1 h with stirring. The resulting solution was diluted with dichloromethane and washed with water. The above process was repeated six times. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 3.28 g (24%) of 4-5 was obtained as an off-white solid. MS m / z [M+H] + (ESI):670.25.

[0121] To a solution of triethylamine trihydrofluoride (7.9 g, 49.0 mmol, 10.0 equiv.) in 20 mL of dry tetrahydrofuran was added triethylamine (9.9 g, 97.9 mmol, 20.0 equiv.) at room temperature under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 10 minutes. A solution of 4-5 (3.28 g, 4.9 mmol, 1.0 equiv.) in 12 mL of dry tetrahydrofuran was added to the resulting solution. The reaction mixture was stirred overnight at room temperature, diluted with 200 mL of dichloromethane, and washed with 2 × 200 mL of saturated aqueous sodium bicarbonate and 2 × 200 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by flash preparative HPLC (IntelFlash-1) under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (30% acetonitrile up to 100% in 10 min, held at 100% for 5 min); detector, UV 254 nm. 1.3 g (62%) of 4-6 was obtained as a yellow oil. MS m / z [M+H] + (ESI):432.15. H NMR(400MHz,DMSO-d6)δ 11.50-11.29(m,1H),8.89(s,1H),7.76(d,J=8.1Hz,1H),6.45(d,J=5.0Hz,1H),6.05(d,J=6.0Hz,1H),5.66(m ,1H),5.52(d,J=6.1Hz,1H),4.68(m,1H),4.16(t,J=4.8Hz,1H),4.07(m,3.7Hz,4H),3.36(s,3H),1.24(m,6H).

[0122] To a solution of 4-6 (1 g, 2.318 mmol, 1.0 equiv.) in 10 mL of dichloromethane was added 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite (838.6 mg, 2.782 mmol, 1.2 equiv.) and 4,5-dicyanoimidazole (273.8 mg, 2.318 mmol, 1.0 equiv.) at room temperature. The resulting solution was stirred at room temperature for 1 hour. The reaction solution was diluted with 300 mL of dichloromethane and washed with 2 × 100 mL of saturated aqueous sodium bicarbonate and 1 × 100 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure until no residual solvent remained. The crude product was purified by flash preparative HPLC (IntelFlash-1) using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (from 30% acetonitrile up to 100% in 15 min, held at 100% for 5 min); detector, UV 254 nm. The residue was diluted with an equal volume of dichloromethane. The organic layer was separated. The aqueous phase was extracted with 3 x 50 mL of dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solid was filtered. The filtrate was concentrated at 25 °C. 840.5 mg (57%) of 4-0 was obtained as a white solid. MS m / z [M−H] - (ESI):630.20. H NMR(300MHz,DMSO-d6)δ 11.43(s,1H),8.90(s,1H),7.65(m,1H),6.48(d,J=4.4Hz,1H),5.80-5.56(m,2H),4.95(m,1H),4.24(m,1H),4.16-3.95(m,4H),3.82 -3.63(m,2H),3.62-3.40(m,2H),3.37(d,J=3.5Hz,3H),2.76(m,2H),1.32-1.16(m,7H),1.09(t,J=6.8Hz,8H),0.96d,J=6.8Hz,3H). P NMR(121MHz,DMSO)δ 150.00,149.96,7.37,7.35.

[0123] Examples 2-4

[0124] [ka]

[0125] To a solution of L-ascorbic acid (125 g, 0.71 mol, 1.0 equiv.) in 1 L of water under an inert atmosphere of argon, calcium carbonate (125 g, 1.25 mol, 1.76 equiv.) was slowly added over 30 min. To the resulting solution, hydrogen peroxide (250 mL, 30% aqueous) was added dropwise over 1 h with stirring at 0 °C. The reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was then filtered, and the filter cake was washed with 2 × 100 mL of water. The filtrate was treated with activated carbon (25 g) and then heated to 70 °C. The hot suspension was filtered, and the solid material was washed with 2 × 50 mL of water. The combined filtrate was crystallized by adding 2 volume equivalents of methanol with stirring at 4 °C for 16 h. The solid material was filtered, washed with 2 × 50 mL of methanol, and dried under high vacuum at 40 °C. 88.1 g (75%) of 1 was obtained as a white solid. No MS signal. 1 H NMR (400MHz, D2O): δ 3.98 (d, J=2.2Hz, 1H), 3.88-3.72 (m, 1H), 3.62-3.49 (m, 2H).

[0126] To a solution of 1 (100 g, 0.30 mol, 1.0 equiv.) in 500 mL of dry acetonitrile under an inert atmosphere of argon, anhydrous oxalic acid (28.8 g, 0.32 mol, 1.0 equiv.) and p-toluenesulfonic acid monohydrate (1.0 g, 0.01 equiv.) were added sequentially at room temperature. The mixture was stirred under reflux for 3 hours. The hot mixture was cooled to room temperature and filtered. The filter cake was washed with 50 mL of acetonitrile, and the combined filtrates were evaporated under reduced pressure. The residue was dissolved in 100 mL of ethyl acetate and evaporated to dryness. 50.1 g (70%) of 2 was obtained as a white solid. MS m / z [M+H] + (ESI): 119. This was used in the next step without further purification.

[0127] To a mixed solution of 2 (66.5 g, 0.56 mol, 1.0 equiv.) in 1200 mL of dichloromethane and 135 mL of anhydrous pyridine was added benzoyl chloride (72.0 mL, 0.62 mol, 1.1 equiv.) dropwise at 0°C under an inert atmosphere of argon. The resulting solution was stirred at 0°C for 30 min. The reaction mixture was quenched with 1 N HCl and washed with 3 x 200 mL of saturated aqueous sodium chloride. Two volume equivalents of hexane were added to the organic layer over 1 h and stirred at 0°C for 16 h. The desired product was collected by filtration and dried under vacuum. 75.1 g (60%) of 3 was obtained as a white solid. MS m / z [M+H] + (ESI):223. 1 H NMR(400MHz,DMSO-d6):δ 8.08-7.98(m,2H),7.78-7.67(m,1H),7.59-7.51(m,2H),6.12(d,J=17.9Hz,1H) ,5.73(d,J=7.9Hz,1H),4.74-4.71(m,1H),4.55-4.44(m,1H),4.09-4.03(m,1H).

[0128] To a solution of 3 (16.5 g, 74.3 mmol, 1.0 equiv.) in 160 mL of dichloromethane was added 4-dimethylaminopyridine (60 mg, 6.0 mmol, 0.01 equiv.), imidazole (10.2 g, 150 mmol, 2.0 equiv.), and tert-butyldiphenylchlorosilane (21.4 g, 75.0 mmol, 1.05 equiv.) in sequence at 0 °C under an inert atmosphere of argon. The reaction mixture was allowed to warm to room temperature and stirred overnight. The resulting solution was evaporated under reduced pressure. The residue was dissolved in 300 mL of hexane and washed with 1 × 100 mL of 1 N HCl, 3 × 100 mL of water, and 3 × 100 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. This was used in the next step without further purification. MS m / z [M+H] + (ESI):461.

[0129] To a solution of crude 4 (35.0 g, 76 mmol, 1.0 equiv) in 150 mL of 1,2-dimethoxyethane under an inert atmosphere of argon, diisobutylaluminum hydride (100 mL, 100 mmol, 1 M solution in toluene) was added dropwise over 10 min at −78° C. The mixture was stirred at −78° C. for 30 min. The reaction was monitored by TLC and used in the next step without further purification.

[0130] To a solution of 5, a pre-prepared solution containing acetic anhydride (35 mL, 367 mmol, 5.0 equiv.) and 4-dimethylaminopyridine (14.0 g, 115 mmol, 1.5 equiv.) in 40 mL of dichloromethane was added dropwise at −78°C under an inert atmosphere of argon. After stirring for 10 minutes, the reaction mixture was warmed to room temperature and stirred for 2 hours. The mixture was diluted with 200 mL of hexane and poured into 200 mL of cold 1N aqueous HCl. The organic layer was washed with 3 × 100 mL of water, 3 × 100 mL of saturated aqueous sodium bicarbonate, and 3 × 100 mL of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude material was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.1% FA) and acetonitrile (20% acetonitrile up to 100% in 10 min, held at 100% acetonitrile for 8 min), UV 254 nm. The fractions were diluted with dichloromethane and dried over anhydrous sodium sulfate. The solids were filtered, and the filtrate was concentrated under reduced pressure. 21.1 g (56% over three steps) of 6 was obtained as a colorless oil. MS m / z [M+H] + (ESI):505. 1 H NMR(300MHz,DMSO-d6):δ 7.89-7.82(m,2H),7.71-7.62(m,5H),7.57-7.28(m,8H),6.44-6.09(m,1H),5.48-5.25(m,1 H),4.76-4.59(m,1H),4.19-3.83(m,2H),2.14(s,2H),1.86(s,1H),1.04(d,J=15.2Hz,9H).

[0131] To a solution of 6 (10.0 g, 59.4 mmol, 1.0 equiv.) in 50 mL of anhydrous acetonitrile under an inert atmosphere of argon, uracil (3.3 g, 29.7 mmol, 1.5 equiv.) and N,O-bis(trimethylsilyl)acetamide (8.1 g, 39.6 mmol, 2.0 equiv.) were added sequentially at room temperature. The mixture was stirred at 60 °C for 30 min. Trimethylsilyl trifluoromethanesulfonate (7.0 g, 31.7 mmol, 1.5 equiv.) was then added dropwise and stirred at 60 °C for an additional 2 h. The reaction mixture was cooled to room temperature, diluted with 200 mL of ethyl acetate, and poured into 100 mL of cold saturated aqueous sodium bicarbonate. The organic layer was washed with 3 × 100 mL of water and 3 × 100 mL of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was used directly in the next step without further purification. MS m / z [M+H] + (ESI):557.

[0132] To a solution of triethylamine trihydrofluoride (28.9 g, 17.9 mmol, 10.0 equiv.) in 50 mL of dry tetrahydrofuran was added triethylamine (36.4 g, 35.9 mmol, 20.0 equiv.) at room temperature under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 10 minutes. A solution of 7 (10.0 g, 53.9 mmol, 1.0 equiv.) in 50 mL of dry tetrahydrofuran was added to the resulting solution. The reaction mixture was stirred overnight at room temperature, diluted with 300 mL of dichloromethane, and washed with 2 × 100 mL of saturated aqueous sodium bicarbonate and 2 × 100 mL of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.1% FA) and acetonitrile (10% acetonitrile up to 100% in 12 min), UV 254 nm. The fractions were diluted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. 5.0 g (80% over two steps) of 8 was obtained as a pale yellow solid. MS m / z [M+H] + (ESI):319. 1H NMR(400MHz,DMSO-d6):δ 11.35(d,J=2.2Hz,1H),8.05-7.94(m,2H),7.76(d,J=8.2Hz,1H),7.73-7.65(m,1H),7.54-7.32(m,2H) ),5.92-5.75(m,2H),5.67-5.46(m,1H),5.26(d,J=1.8Hz,1H),4.36-4.25(m,1H),4.14-3.89(m,2H).

[0133] To a solution of 8 (10.0 g, 31.4 mmol, 1.0 equiv.) in 80 mL of dry dichloromethane under an inert atmosphere of argon, 2,4,6-collidine (22.8 g, 188.1 mmol, 6.0 equiv.) and 4,4'-dimethoxytrityl chloride (26.6 g, 78.7 mmol, 2.5 equiv.) were added sequentially at room temperature. The resulting solution was stirred at room temperature for 24 h. The reaction mixture was quenched with 10 mL of methanol, diluted with 500 mL of dichloromethane, and washed with 2 × 200 mL of saturated aqueous sodium bicarbonate and 2 × 200 mL of saturated aqueous sodium chloride, respectively. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was dissolved in 400 mL of ammonia (7 M NH3 in methanol) and stirred at room temperature for 24 h under an inert atmosphere of argon. The reaction mixture was concentrated under reduced pressure. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (15% acetonitrile up to 100% in 10 min, held at 100% acetonitrile for 6 min), UV 254 nm. The fractions were diluted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. 12.1 g (75%) of 81 was obtained as a pale yellow oil. MS m / z [MH] - (ESI):515.

[0134] To a solution of 81 (10.0 g, 19.4 mmol, 1.0 equiv.) in 100 mL of dry N,N-dimethylformamide was added imidazole (3.9 g, 57.3 mmol, 3.0 equiv.) and tert-butyldimethylsilyl chloride (8.8 g, 58.1 mmol, 3.0 equiv.) sequentially at room temperature under an inert atmosphere of argon. The resulting solution was stirred at room temperature for 12 h. The reaction mixture was diluted with 500 mL of dichloromethane and washed with 2 × 200 mL of saturated aqueous sodium bicarbonate and 1 × 200 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was dissolved in 120 mL of dichloromethane, and trifluoroacetic acid (21.7 g, 190.5 mmol, 10.0 equiv.) and triethylsilane (11.1 g, 95.2 mmol, 5.0 equiv.) were added sequentially at room temperature. The mixture was stirred at room temperature for 1 hour under an inert atmosphere of argon. The reaction mixture was diluted with 400 mL of dichloromethane and washed with 2 × 150 mL of saturated aqueous sodium bicarbonate and 1 × 150 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash preparative HPLC using the following conditions: column, C18 silica gel; mobile phase, water (containing 0.1% FA) and acetonitrile (15% acetonitrile up to 100% in 10 min, held at 100% acetonitrile for 6 min), UV 254 nm. The fraction was diluted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. Obtained 4.7 g (75%) of 82 as a pale yellow solid. MS m / z [M−H] - (ESI):515. 1 H NMR(300MHz,DMSO-d6):δ 11.29(s,1H),7.62(d,J=8.2Hz,1H),5.58-5.55(m,2H),5.43(d,J=2.6Hz,1H),4.17-3.94(m,4H),0.86(s,9H),0.10(d,J=4.0Hz,6H).

[0135] To a solution of 82 (4.0 g, 11.9 mmol, 1.0 equiv.) in 40 mL of dry tetrahydrofuran was added (diethoxyphosphoryl)methyl 4-methylbenzenesulfonate (7.7 g, 23.9 mmol, 2.0 equiv.) at room temperature under an inert atmosphere of argon. Sodium hydride (1.9 g, 47.7 mmol, 4.0 equiv.) was added to the reaction mixture at 0 °C and stirred at the same temperature for 3 h under an inert atmosphere of argon. The reaction was quenched with 6 mL of acetic acid (1 M), diluted with 150 mL of ethyl acetate, and washed with 1 × 50 mL of HO and 1 × 50 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was applied to a silica gel column with ethyl acetate / petroleum ether (1:10 to 5:1). The desired product fraction was concentrated under reduced pressure. Obtained 2.5 g (60%) of 53 as a pale yellow oil. MS m / z [M+H] + (ESI):479. 1 H NMR(400MHz,DMSO-d6):δ11.32(s,1H),7.53(d,J=8.1Hz,1H),5.60(d,J=1.1Hz,1H),5.51(d,J=8.1H z,1H),4.35-4.28(m,2H),4.07-3.84(m,8H),1.24-1.20(m,6H),0.87(s,9H),0.13(d,J=2.5Hz,6H). 31 P NMR (162MHz, DMSO): δ 20.74.

[0136] A mixed solution of 53 (3.2 g, 6.7 mmol, 1.0 equiv.) in 32 mL of formic acid and HO (v / v = 1:1) was stirred at room temperature for 24 h under an inert atmosphere of argon. The resulting solution was concentrated under reduced pressure. The crude product was diluted with 300 mL of ethyl acetate and washed with 2 × 50 mL of water and 1 × 50 mL of saturated aqueous sodium bicarbonate, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water and acetonitrile (15% acetonitrile up to 35% in 20 min), UV 254 nm. The fractions were diluted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. 1.9 g (80%) of 14 was obtained as a pale yellow oil. MS m / z [M+H] + (ESI):365. 1 H NMR(300MHz,DMSO-d6):δ 11.31(s,1H),7.55(d,J=8.1Hz,1H),5.94(d,J=4.1Hz,1H),5.68(d,J=1.4Hz,1H),5.53(d,J=8.1Hz ,1H),4.28(d,J=10.2Hz,1H),4.17(s,1H),4.09-3.97(m,6H),3.95-3.84(m,2H),1.23-1.09(m,6H). 31 P NMR (121MHz, DMSO): δ 20.84.

[0137] To a solution of 14 (2.2 g, 6.0 mmol, 1.0 equiv.) in 20 mL of dichloromethane, 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite (2.4 g, 7.8 mmol, 1.3 equiv.) and 4,5-dicyanoimidazole (785 mg, 6.6 mmol, 1.1 equiv.) were added sequentially at room temperature under an inert argon atmosphere. The reaction mixture was stirred at room temperature for 1 h. The reaction solution was diluted with 200 mL of dichloromethane and washed with 2 × 100 mL of saturated aqueous sodium bicarbonate and 1 × 100 mL of saturated aqueous sodium chloride, respectively. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure until no residual solvent remained. The residue was purified by flash preparative HPLC under the following conditions: column, C18 silica gel; mobile phase, water (containing 0.04% NH4HCO3) and acetonitrile (20% acetonitrile up to 100% in 10 min, held at 100% acetonitrile for 5 min). The fractions were diluted with 500 mL of dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. 2.2 g (70%) of 100 was obtained as a pale yellow oil. MS m / z [M+H] + (ESI):565. 1 H NMR (300 MHz, acetonitrile-d3): δ 9.05 (s, 1H), 7.57-7.54 (m, 1H), 5.88-5.83 (m, 1H), 5.57-5.47 (m, 1H), 4.55-4.41 (m, 1H), 4.39-4.29 (m, 1H), 4.23-4.00 (m, 6H), 3.95-3.76 (m, 4H), 3.73-3.57 (m, 2H), 2.75-2.65 (m, 2H), 1.31-1.27 (m, 6H), 1.22-1.19 (m, 12H). 31 P NMR (121MHz, CD3CN): δ 151.05, 150.14, 19.82, 19.71.

[0138] Examples 2-5

[0139] [ka]

[0140] To a solution of 1 (120.0 g, 461.5 mmol) and KOH (31.0 g, 553.6 mmol) in DMF (500.0 mL), BnBr (118.0 g, 690.1 mmol) was added at 0 °C over 30 min, and then it was stirred at room temperature overnight. 1 was completely consumed as monitored by LC-MS and TLC. The reaction was dissolved in water, and the pH was adjusted to pH = 9 by slowly adding solid NaHCO3, and then it was diluted with EA (700.0 mL). * The organic layer was extracted with water (1.0 L). * 2) and anhydrous NaCl, dried over anhydrous Na2SO4, and evaporated in vacuo to give crude product 2 (150.0 g, crude) as a white oil. ESI-MS: m / z 334.1.

[0141] The crude product 2 (150.0 g, crude) was dissolved in 70% AcOH in H2O (700.0 mL) at room temperature, which was then stirred overnight at room temperature. TLC showed that 2 was completely consumed. The reaction was quenched with solid aqueous NaHCO3, which was then diluted with EA (700.0 mL). * The organic layer was extracted with water (1.0 L). * The crude product was purified by column chromatography (SiO, PE / EA = 2:1 to 0:1) to give 3 (110.0 g, 90.5% purity, 76.8% yield) as a pale yellow solid. ESI-MS: m / z 333.1; 1 HNMR(400MHz,CDCl3):δ 7.36(m,5H),5.76(d,J=3.72Hz,1H),4.78(d,J=11.28Hz,1H),4.60(t,J=4.04Hz,1H),4.56(d,J=11.2 8Hz, 1H), 4.11 (m, 1H), 4.00 (m, 1H), 3.93 (m, 1H), 3.67 (m, 2H), 2.55 (s, 2H), 1.59 (s, 3H), 1.36 (s, 3H).

[0142] To a stirred solution of 3 (110.0 g, 350.0 mmol) in DCM (1.2 L) at room temperature was added a solution of NaIO (153.0 g, 710 mmol) in HO (600.0 mL), which was then stirred at room temperature for 1.0 h. The workup was monitored by TLC for completion. The reaction was dissolved in water and diluted with DCM (700.0 mL). * The organic layer was extracted with water (1.0 L). * 2) and aqueous NaCl, dried over anhydrous NaSO, and concentrated under reduced pressure to give 4 (92.0 g, crude) as a pale yellow oil. ESI-MS: m / z 262.1; 1 HNMR(400MHz,CDCl3):δ 9.60(d,J=1.76Hz,1H),7.35(m,5H),5.81(d,J=3.44Hz,1H),4.74(d,J=12. 12Hz,1H),4.60(m,2H),4.48(dd,J=1.68Hz and 9.24Hz,1H),3.85(q,J=4.28Hz 1H), 1.60(s, 3H), 1.37(s, 3H).

[0143] To a solution of 4 (85.0 g, crude) in THF (300.0 mL) was added dropwise a solution of MeLi in diethoxymethane (1.6 M, 287.0 mL) at 0 °C over 0.5 h, and the reaction was then stirred at 0 °C for 2.5 h. TLC showed that 4 was completely consumed. The reaction was quenched with aqueous NH4Cl and it was diluted with EA (400.0 mL). * The organic layer was extracted with water (1.0 L). * 2) and aqueous NaCl, dried over anhydrous NaSO, and evaporated in vacuo to give 5 (86.6 g, crude) as a pale yellow oil. ESI-MS: m / z 278.1; 1 HNMR(400MHz,CDCl3):δ 7.36(m,5H),5.73(d,J=3.6Hz,1H),4.76(m,1H),4.58(m,2H),4.02(m,1H),3.91 (m,1H),3.81(m,1H),1.59(s,3H),1.36(m,3H),1.25(dd,J=6.6Hz,19.2Hz,3H).

[0144] A mixture of 5 (86.6 g, crude) and 2-iodoxybenzoic acid (165.0 g, 589.3 mmol) in ACN (1.0 L) was stirred at 80 °C for 2 h, and then TLC showed that 5 was completely consumed. It was then filtered, and the organic layer was concentrated to give the crude product, which was purified by column chromatography (SiO, PE / EA = 10:1 to 8:1) to give 6 (48.6 g, 90% purity, 56.5% yield) as a yellow solid. ESI-MS: m / z 276.1; 1 HNMR(400MHz,CDCl3)δ 7.36(m,5H),5.82(d,J=3.56Hz,1H),4.77(d,J=11.96Hz,1H),4.60(m,2H), 4.52(d,J=9.16Hz,1H),3.77(m,1H),2.19(s,3H),1.60(s,3H),1.37(s,3H).

[0145] To a stirred solution of diethyl ethylphosphonate (20.7 g, 124.7 mmol) in dry THF (600 mL) was added n-BuLi (1.6 M, 86.0 mL) dropwise at −70° C., and it was stirred at −70° C. for 0.5 h. 6 (40.0 g, 137.0 mmol) in THF (300 mL) was added over 20 min at −70° C., and it was stirred at −70° C. for 2 h. LCMS showed that 6 was completely consumed. It was quenched with aqueous NH4Cl and EA (600 mL) was added. * The organic layer was extracted with water (600.0 mL). * The organic layer was washed with 2) and aqueous NaCl, dried over anhydrous NaSO, filtered, and then concentrated. The crude product was purified by column chromatography (SiO, PE / EA=1:1) to give 7 (33.6 g, 73.3 mmol, 93% purity) as a yellow solid. ESI-MS: m / z 459.2 [M+H] + ; 1 HNMR(400MHz,CDCl3)δ 7.34(m,5H),5.77(m,1H),4.83-4.71(m,1H),4.64-4.52(m,2H),4.23-3.86(m,7H),1.75(m,1H),1.58(t,J=7.6Hz,3H),1.30(m,15H). 31P-NMR (162MHz, CDCl3)δ=33.74,32.93,32.19,31.53.

[0146] To a solution of 7 (33.6 g, 73.4 mmol) in pyridine (200.0 mL), SOCl2 (86.5 g, 73.3 mmol) was added in an ice bath over 30 min, and it was stirred at room temperature for 30 min. LCMS showed that 7 was completely consumed. The mixture was quenched with aqueous NaHCO3 (200.0 mL) and EA (400.0 mL) was added. * The mixture was extracted with 2) and washed with aqueous NaCl solution. After drying over anhydrous NaSO and filtration, the organic layer was concentrated to give the crude product, which was purified by column chromatography (SiO, PE / EA=1:1) to give 8 (25.0 g, 56.8 mmol) as a pale yellow solid. ESI-MS: m / z 441.2 [M+H] + ; 1 HNMR(400MHz,CDCl3)δ 7.34(m,5H),5.78(t,J=3.32Hz,1H),5.43(m,1H),5.31(m,J=5.36Hz 1H),4.75(m,1H),4.56(m,3H),4.07(m,4H),3.69(m,1H),2.81(m,1H),1.60(s,3H),1.30(m,12H); 31 P-NMR(162MHz, CDCl3)δ =30.33,29.97.

[0147] To a solution of 8 (25.5 g, 56.0 mmol) in CHOH (200.0 mL) was added Pd / C (3.8 g, 15%) at room temperature, which was stirred at room temperature for 30 min under an atmosphere of N, and then it was filtered. Another portion of Pd / C (3.8 g, 15%) was added, and it was stirred at 50 °C for 3 h. LCMS showed that 8 was completely consumed. After filtration, the organic layer was concentrated to give the crude product, which was purified by column chromatography to give 9 (15.0 g, 34.0 mmol, 58.6% yield) as a pale yellow oil. ESI-MS: m / z 443.5 [M+H] + ; 1HNMR(400MHz,CDCl3)δ 7.35(m,5H),5.69(m,1H),4.81-4.73(m,1H),4.60-4.49(m,2H),4.14-4.01( m,5H),3.56-3.48(m,1H),2.47-2.10m,2H),1.58(m,3H),1.37-1.23(m,15H). 31 P-NMR (162MHz, CDCl3)δ=34.76,34.17,33.95,33.55.

[0148] A solution of 9 (15.0 g, 34.0 mmol) in 60% AcOH / H2O (75.0 mL) was stirred at 100 °C for 3 h. TLC showed that 9 was completely consumed, and then it was concentrated in vacuo to give the crude intermediate. The crude intermediate and DMAP (828.0 mg, 6.8 mmol) were dissolved in dry pyridine (60.0 mL), and then Ac2O (20.8 g, 203.9 mmol) was added at 0 °C for 10 min. It was stirred at room temperature for 2 h and then monitored for completion by LCMS. The mixture was quenched with aqueous NaHCO3 (100.0 mL) and EA (100.0 mL) was added. * 2). The organic layer was washed with aqueous NaCl and dried over anhydrous Na2SO4. After filtration, the organic layer was concentrated to give the crude product, which was purified by column chromatography to give 10 (13.8 g, 28.4 mmol, 83.7% yield) as a yellow oil. ESI-MS: m / z 509.2 [M+Na] + ; 1 HNMR(400MHz,CDCl3)δ 7.36-7.23(m,5H),6.36-6.07(m,1H),5.36-5.04(m,1H),4.65-4.52(m,1H),4.49-4.42(m,1H), 4.34-4.84(m,6H),2.45-2.18(m,1H),2.13-2.04(m,6H),1.95-1.69(m,1H),1.35-0.95(m,12H). 31 PNMR(162MHz, CDCl3)δ=34.43,34.17,34.15,33.56,33.44,33.39,32.61.

[0149] A solution of uracil (4.1 g, 36.3 mmol) and BSA (15.9 g, 77.7 mmol) in dry ACN (80.0 mL) was stirred at 50 °C until the mixture became clear. Then, a solution of 10 (11.8 g, 24.3 mmol) in dry ACN (40.0 mL) was added, and TMSOTf (5.5 g, 24.8 mmol) was added dropwise at room temperature over 30 min. The mixture was stirred at room temperature for 5 h. LMCS showed that 10 was completely consumed. The mixture was quenched with aqueous NaHCO (100.0 mL) and extracted with EA (200.0 mL * 2). The organic layer was washed with aqueous NaCl and dried over anhydrous NaSO. After filtration, the organic layer was concentrated to give the crude product, which was purified by column chromatography (SiO, PE:EA=1:2) to give 11 (10.3 g, 19.1 mmol, 78.8% yield) as a yellow solid. ESI-MS: m / z 539.1 [M+H] + ; 1 HNMR(400MHz,CDCl3)δ 9.94-9.86(m,1H),7.37-7.27(m,6H),5.77-5.71(m,2H),5.45-5.29(m,1H),4.60-4.46(m,2H),4.32-4.2 6(m,1H),4.14-4.03(m,5H),2.38-2.34(m,1H),2.22-2.16(m,1H),2.11-2.08(m,3H),1.38-1.02(m,12H). 31 PNMR(162MHz, CDCl3)δ=34.16,33.56,33.29,33.03,32.44.

[0150] A solution of 1110.3 g, 19.1 mmol) in CH3NH2 (100.0 mL, 30% in MeOH) was stirred at room temperature for 1 h. LCMS showed that 11 was completely consumed. The mixture was then concentrated in vacuo to give 12 (11.0 g, crude). ESI-MS: m / z 497.2 [M+H] + ; 31 PNMR(162MHz, CDCl3)δ=34.18,33.17,33.02,33.03,32.40.

[0151] To a stirred solution of 12 (9.1 g, crude) and DBU (8.4 g, 55.2 mmol) in dry DMF (50.0 mL) was added benzyl chloromethyl ether (5.7 g, 36.4 mmol) at 0 °C over 10 min. The mixture was then stirred at room temperature overnight. LCMS showed that 12 was completely consumed. The mixture was then quenched with aqueous NaHCO (50.0 mL) and EA (100.0 mL) was added. * 2). The organic layer was washed with aqueous NaCl and dried over anhydrous Na2SO4. After filtration, the organic layer was concentrated to give the crude product, which was purified by column chromatography (SiO2, PE:EA=1:1) to give 13 (7.0 g, 11.4 mmol, 59.4% yield). ESI-MS: m / z 617.4 [M+H] + ; 1 H NMR(400MHz,CDCl3)δ 9.94-9.86(m,1H),7.38-7.17(m,11H),5.83-5.74(m,2H),5.66-5.43(m,3H),4.78-4.55(m,4H),4.37-4.29(m,1 H),4.22-3.93(m,6H),3.10-2.99(m,1H),2.45-2.11(m,1H),2.04-1.93(m,3H),1.65(m,1H),1.34-1.03(m,12H). 31 PNMR(162MHz, CDCl3)δ=34.15,33.17,33.03,33.46.

[0152] A solution of 13 (7.0 g, 10.2 mmol), NaI (767.0 mg, 5.1 mmol), and AgO (3.6 g, 15.3 mmol) in MeI (30.0 mL) was stirred at 40 °C for 1 h, and LCMS showed that 13 was completely consumed. After filtration, the organic layer was concentrated to give the crude product, which was purified by column chromatography (SiO, PE:EA = 1:1) to give 14-P1 (3.9 g, 6.2 mmol) and 14-P2 (3.1 g, 4.9 mmol) as yellow solids. ESI-MS: m / z 631.3 [M+H] + ;14-P1: 31 PNMR(162MHz,CDCl3)δ=33.03,32.85;14-P2:31 PNMR(162MHz, CDCl3)δ=34.27,33.55.

[0153] A solution of 14-P1 (3.9 g, 6.2 mmol) in CF3COOH (20.0 mL) was stirred at 80 °C for 1 h, and LCMS showed that 14 was completely consumed. After concentration, the crude product was purified by column chromatography (SiO2, PE:EA = 0:1) to give a mixed product (2.5 g, 93% purity, 96.2% yield). The mixture was separated by SFC to give isomer 1 of 15 (500.0 mg, 1.2 mmol, 20.0% yield) and isomer 2 of 15 (760 mg, 1.8 mmol, 30.4% yield) as white solids. A solution of 14-P2 (3.1 g, 4.9 mmol) in CF3COOH (20.0 mL) was stirred at 80 °C for 1 h, and LCMS showed that 14-P2 was completely consumed. After concentration, the crude product was purified by column chromatography (SiO, PE:EA = 0:1) to give a mixed product (1.6 g, 91% purity, 77.4% yield). The mixture was separated by SFC to give 15 isomer 3 (130.0 mg, 0.3 mmol, 8.1% yield) and 15 isomer 4 (800 mg, 1.9 mmol, 50.0% yield) as white solids.

[0154] Isomer 1 of 15: 1 HNMR(400MHz,CDCl3)δ 8.98(s,1H),7.33(d,J=8.12Hz,1H),5.76(m,2H),4.24(t,J=7.9Hz,1H),4.11(m,5H),3.8 9(d,J=5.6Hz,1H),3.59(s,3H),2.38-2.27(m,1H),2.15-2.04(m,1H),1.35-1.18(m,12H). 31 PNMR(162MHz,CDCl3)δ=33.29;ESI-MS:m / z 421.2[M+H] +

[0155] Isomer 2 of 15: 1HNMR(400MHz,CDCl3)δ 8.69(s,1H),7.40(d,J=8.1Hz,1H),5.72-5.69(m,2H),4.04-3.97(m,5H),3.83(q,J=6.2Hz ,1H),3.72(m,1H),3.52(s,3H),2.27-2.16(m,1H),2.03-1.88(m,1H),1.26-1.17(m,12H). 31 PNMR(162MHz,CDCl3)δ=33.56;ESI-MS:m / z 421.2[M+H] +

[0156] 15のheterosexual body 3: 1 HNMR(400MHz,CDCl3)δ 8.69(s,1H),7.40(d,J=8.1Hz,1H),5.83-5.76(m,2H),4.20-4.05(m,4H),3.91-3.88(m,1H),3.7 4-3.71(m,2H),3.61(s,3H),2.46-2.31(m,2H),1.35-1.32(t,J=7.04Hz,6H),1.19-1.12(m,6H). 31 PNMR(162MHz,CDCl3)δ=33.51;ESI-MS:m / z421.2[M+H] +

[0157] 15のheterosexual body 4: 1 HNMR(400MHz,CDCl3)δ 8.89(s,1H),7.33(d,J=8.04Hz,1H),5.82-5.70(m,2H),4.11-4.02(m,4H),3.88(m,1H),3.7 2(s,1H),3.63(t,J=6.2Hz,9.28Hz,1H),3.52(s,3H),2.38-2.23(m,2H),1.27-1.01(m,12H). 31 PNMR(162MHz,CDCl3)δ=34.18;ESI-MS:m / z 421.1[M+H] +

[0158] A's synthesis To a stirred solution of 15 isomer 1 (500 mg, 1.2 mmol) and DCI (126.4 mg, 1.1 mmol) in dry DCM (5.0 mL) under a N atmosphere was added CEP[N(iPr)] (430.0 mg, 1.4 mmol). The mixture was stirred at 30 °C for 1 h. LCMS showed that 15 isomer 1 was completely consumed. The solution was then diluted with DCM (10 mL) and HO (10 mL). * The mixture was washed with HCl (3). After drying over anhydrous NaSO, the organic layer was concentrated under reduced pressure, and the residue was purified by flash preparative HPLC (IntelFlash-1) under the following conditions: column, C18 silica gel; mobile phase, CHCN / H2O (0.5% NH4HCO3) = 1 / 1, increasing to CHCN / H2O (0.5% NH4HCO3) = 1 / 0 within 20 min; eluted product was collected by CH3CN / H2O (0.5% NH4HCO3) = 6 / 1; detector, UV 254 nm. This afforded A (500 mg, 0.8 mmol, 95% purity, 65% yield) as a white solid. ESI-MS: m / z 619.2 [MH] - ; 1 HNMR(400MHz,CDCl3)δ 9.10(s,1H),7.30(m,J=8.4Hz,1H),5.82(t,J=4.4Hz,1H),5.76(d,J=8.4Hz,1H),4.34(m,1H),4.10(m,5H),3 .84(m,5H),3.48(m,5H),3.50(m,3H),2.72-2.66(m,2H),2.20(m,1H),2.04-1.97(m,1H),1.34-1.17(m,24H); 31 P NMR(162MHz, CDCl3)δ=149.59,33.43,34.03.

[0159] Synthesis of B To a stirred solution of 15 isomer 2 (760 mg, 1.8 mmol) and DCI (192.2 mg, 1.6 mmol) in dry DCM (5.0 mL) under a N atmosphere was added CEP[N(iPr)] (653.6 mg, 2.1 mmol). The mixture was stirred at 30 °C for 1 h. LCMS showed that 15 isomer 2 was completely consumed. The solution was then diluted with DCM (10 mL) and HO (10 mL).* The mixture was washed with HCl (3). After drying over anhydrous NaSO, the organic layer was concentrated under reduced pressure, and the residue was purified by flash preparative HPLC (IntelFlash-1) under the following conditions: column, C18 silica gel; mobile phase, CHCN / H2O (0.5% NH4HCO3) = 1 / 1, increasing to CHCN / H2O (0.5% NH4HCO3) = 1 / 0 within 20 min; eluted product was collected by CH3CN / H2O (0.5% NH4HCO3) = 6 / 1; detector, UV 254 nm. This afforded B (500 mg, 0.8 mmol, 95% purity, 45% yield) as a white solid. ESI-MS: m / z 619.2 [M−H] - ; 1 HNMR(400MHz,CDCl3)δ 9.40(s,1H),7.45(m,1H),5.77(m,2H),4.27-3.60(m,11H),3.49(d,J=14 Hz, 3H), 2.66 (m, 2H), 2.38-2.30 (m, 1H), 2.01 (m, 1H), 1.33-1.15 (m, 24H). 31 PNMR(162MHz, CDCl3)δ=149.35,32.76,32.73.

[0160] Synthesis of C To a stirred solution of isomer 3 of 15 (130 mg, 0.3 mmol) and DCI (32.9 mg, 0.3 mmol) in dry DCM (2.0 mL) under a N atmosphere was added CEP[N(iPr)] (111.8 mg, 0.4 mmol). The mixture was stirred at 30 °C for 1 h. LCMS showed that isomer 3 of 15 was completely consumed. The solution was then diluted with DCM (10 mL) and HCl (10 mL). *The mixture was washed with HCl (3). After drying over anhydrous NaSO, the organic layer was concentrated under reduced pressure, and the residue was purified by flash preparative HPLC (IntelFlash-1) under the following conditions: column, C18 silica gel; mobile phase, CHCN / H2O (0.5% NH4HCO3) = 1 / 1, increasing to CHCN / H2O (0.5% NH4HCO3) = 1 / 0 within 20 min; eluted product was collected by CH3CN / H2O (0.5% NH4HCO3) = 6 / 1; detector, UV 254 nm. This afforded C (110 mg, 0.2 mmol, 95% purity, 57% yield) as a white solid. ESI-MS: m / z 619.2 [MH] - ; 1 HNMR(400MHz,CDCl3)δ 8.50(s,1H),7.31(m,1H),5.84(m,1H),5.75(d,J=8.4Hz,1H),4.16-3.59(m,11H),2.70(m,2H),2.40-2.18(m,2H),1.41-1.12(m,24H). 31 PNMR(162MHz, CDCl3)δ=150.21,149.66,33.61,33.01.

[0161] Synthesis of D To a stirred solution of 15 isomer 4 (800 mg, 1.9 mmol) and DCI (202.3 mg, 1.7 mmol) in dry DCM (5.5 mL) under a N atmosphere was added CEP[N(iPr)] (688.0 mg, 2.3 mmol). The mixture was stirred at 30 °C for 1 h. LCMS showed that 15 isomer 4 was completely consumed. The solution was then diluted with DCM (10 mL) and HO (10 mL). *The mixture was washed with HCl (3). After drying over anhydrous NaSO, the organic layer was concentrated under reduced pressure, and the residue was purified by flash preparative HPLC (IntelFlash-1) under the following conditions: column, C18 silica gel; mobile phase, CHCN / H2O (0.5% NH4HCO3) = 1 / 1, increasing to CHCN / H2O (0.5% NH4HCO3) = 1 / 0 within 20 min; eluted product was collected by CH3CN / H2O (0.5% NH4HCO3) = 6 / 1; detector, UV 254 nm. This afforded D (760 mg, 1.23 mmol, 95% purity, 64% yield) as a white solid. ESI-MS: m / z 619.2 [MH] - ; 1 HNMR(400MHz,CDCl3)δ 9.40(s,1H),7.45(m,1H),6.03(t,J=4.8Hz,1H),5.70(m,1H),4.22-4.06(m,5H),3.94-3.61(m,6H),3.48(d ,J=10.8Hz,3H),2.64(m,2H),2.49-2.29(m,2H),1.39-1.29(m,6H),1.24-1.15(m,12H),1.12-1.04(m,6H). 31 P NMR(162MHz, CDCl3)δ=150.3,149.90,34.52,34.36.

[0162] Example 3: Exemplary synthesis of oxetane VP

[0163] [ka]

[0164] Under a N2 atmosphere, 1 (prepared according to T. Jonckers et al. J. Med. Chem. 2016, 59, 5790-5798) (10.0 g, 25.6 mmol), imidazole (34.9 g, 512 mmol), and DMAP (0.94 g, 7.7 mmol) were dissolved in DMF (100 ml). TBSCl (30.9 g, 205 mmol) was added portionwise at 0 °C. After the addition was complete, the mixture was stirred at 80 °C for 16 h. Saturated aqueous NH4Cl was added to the reaction, and the aqueous layer was extracted with EtOAc (3x). The combined organic layers were washed with 5% aqueous LiCl (2x), dried over Na2SO4, and concentrated in vacuo to give 2 (21.1 g) as a crude product, which was used in the next step without further purification.

[0165] [ka]

[0166] 2 (15.8 g, 25.6 mmol) was dissolved in THF (51.7 mL) and distilled water (13.7 mL). The mixture was cooled to 0 °C, and TFA (13.7 mL) was added dropwise over 15 min, maintaining the internal reaction temperature below 2 °C. The mixture was stirred at 0 °C for 1 h and then at −18 °C for 14 h. The reaction was warmed to 0 °C, and stirring was continued for 4 h, followed by 4 h at 5 °C. The reaction was basified to pH ∼8 with NH OH solution, diluted with water, and the aqueous layer was extracted with EtOAc (3x). The combined organic layers were dried over Na SO and concentrated in vacuo. The crude material was purified by flash silica gel chromatography (DCM / MeOH, gradient 100:0 to 98:2) to give 3 (7.6 g, 59%).

[0167] [ka]

[0168] Under a N atmosphere, 3 (3.0 g, 6.0 mmol) was dissolved in DCM (100 mL). DMP (3.6 g, 8.4 mmol) was added at 0 °C, and the mixture was stirred at 0 °C for 1 h and then at room temperature for an additional 3 h. To the mixture was added a 50 mL mixture of 30% aqueous NaSO and saturated aqueous NaHCO (1:1), and the aqueous layer was extracted with EtOAc (3x). The combined organic layers were dried over NaSO and concentrated in vacuo to give 4 (4.4 g) as a crude product, which was used in the next step without further purification.

[0169] Under a N2 atmosphere, NaH (60% dispersion in mineral oil, 720 mg, 18 mmol) was suspended in THF (10 mL), and the mixture was cooled to -78 °C. A solution of 5 (9.5 g, 14.5 mmol) in THF (11 mL) was added, and the mixture was stirred at -78 °C for 20 min. To this mixture, a solution of 4 (3.0 g, 6 mmol) in THF (21 mL) was added dropwise over 30 min at -78 °C, and stirring was continued at the same temperature for 100 min. The mixture was warmed to 0 °C and stirred for 1 h, followed by stirring at room temperature for an additional 90 min. The crude reaction mixture was poured into 100 mL of saturated aqueous NH4Cl, and the product was extracted into 100 mL of ethyl acetate (2x). The organic layer was washed with brine and dried over anhydrous Na2SO4. The solution was then concentrated under reduced pressure and the residue was purified by flash silica gel chromatography (heptane:EtOAc, gradient from 100:0 to 0:100) to give 6 (2.7 g, 56%) as a 90:10 mixture of E:Z isomers.

[0170] [ka]

[0171] 6 (2.7 g, 2.7 mmol) was dissolved in MeCN (26 mL) and distilled water (8.1 mL). CAN (7.5 g, 13.7 mmol) was added, and the mixture was stirred at room temperature for 24 h. The reaction was basified to pH 6-7 with NH4OH solution, poured into brine solution (50 mL), and extracted with EtOAc (3x). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The crude material was purified by flash silica gel chromatography (DCM / MeOH, gradient 100:0 to 90:10) to give 7 (823 mg, 52%).

[0172] [ka]

[0173] Under a N2 atmosphere, 7 (952 mg, 1.7 mmol) and 4,5-dicyanoimidazole (DCI, 166 mg, 1.4 mmol) were dissolved in dry DCM (9.2 mL). 2-Cyanoethyl-N,N,N',N'-tetraisopropylphosphorosdiamidite (0.684 mL, 2.2 mmol) was added, and the mixture was stirred at room temperature for 16 h. Another portion of 2-cyanoethyl-N,N,N',N'-tetraisopropylphosphorosdiamidite (0.158 mL, 0.5 mmol) was added, and the mixture was allowed to stand at room temperature for 3 h. The organic layer was poured into water and washed with water (2x) and brine (1x). The organic layer was dried over Na2SO4 and concentrated in vacuo. The crude material was purified by flash silica gel chromatography (heptane with 0.15% TEA / EtOAc, gradient 100:0 to 0:100 with 0.15% TEA) to give 8 (532 mg, 41%). 1H NMR(400MHz,DMSO-d6)δ ppm 1.12-1.16(m,18H),1.17-1.24(m,12H),2.52-2.78(m,H),2.79-2.89(m,2H),3.60-3.79(m,3H),3.79-3.91(m,1H),4.16-4.29(m,1H), 4.32-4.56(m,3H),5.56-5.67(m,5H),5.88-5.94(m,1H),6.05-6.21(m,1H),6.67-6.97(m,1H),7.57-7.68(m,1H),11.43-11.50(m,1H). 31 P NMR(162MHz,DMSO-d6)δ ppm 16.4,17.2,148.7,150.7 LCMS:Method A,Rt:1.24,775.5[M+H] +

[0174] [ka]

[0175] To a 5 L three-necked round-bottom flask, chlorodimethylphenylsilane (183.90 g, 1077.25 mmol), imidazole (173.35 g, 2546.24 mmol), and DCM (3000 mL) were added at room temperature. To the above mixture, 9 (200 g, 979.32 mmol) was added dropwise over 2 h at 0 °C. The resulting mixture was further stirred at room temperature overnight. The reaction was quenched with water at room temperature. The resulting mixture was extracted with CHCl (2 × 2 L). The combined organic layers were washed with brine (1 × 2 L) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by flash silica gel chromatography eluting with PE / EA = 10:1 to give 10 (260 g, 78%).

[0176] [ka]

[0177] To a 10 L four-neck round-bottom flask, LiBH (50.19 g, 2304.45 mmol) and THF (6500 mL) were added at room temperature. To the above mixture, 10 (260 g, 768.15 mmol) was added dropwise over 1.5 h at 0 °C. The resulting solution was stirred overnight at room temperature. The reaction was quenched by adding saturated NH Cl (aqueous) (3 L) at 0 °C. The resulting mixture was extracted with CHCl (2 × 1 L). The combined organic layers were washed with brine (1 × 2 L) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by flash silica gel chromatography, eluting with PE / EA (1:1) to give 11 (120 g, 61%).

[0178] [ka]

[0179] To a 10 L four-neck round-bottom flask, 11 (120 g, 471.69 mmol), DCM (6000 mL), pyridine (37.68 g, 476.41 mmol), and DMAP (5.76 g, 47.17 mmol) were added at room temperature. To the above mixture, AcO (48.64 g, 476.41 mmol) was added dropwise over 1 h at 0 °C. The resulting mixture was further stirred at room temperature overnight. The reaction was quenched with NaHCO (aq) at room temperature. The resulting mixture was extracted with CHCl (2 × 2 L). The combined organic layers were washed with brine (1 × 2 L) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by flash silica gel chromatography eluting with PE / EA (1:1) to give 12 (64 g, 46%).

[0180] [ka]

[0181] To a 1 L three-necked round-bottom flask, uracil (70 g, 624.50 mmol), acetonitrile (210 mL), and pyridine (123.50 g, 1.56 mol) were added at room temperature. To the above mixture, benzyl chloroformate (234.38 g, 1.37 mol) was added dropwise over 1.5 h at 0 °C. The resulting mixture was further stirred at room temperature overnight. The resulting mixture was extracted with EtOAc (2 × 500 mL). The combined organic layers were washed with brine (1 × 500 mL) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure. The crude product was recrystallized from MeOH (200 mL) to give 13 (80 g, 59%).

[0182] [ka]

[0183] To a 3 L three-necked round-bottom flask were added 12 (64 g, 215.89 mmol), PPh3 (124.58 g, 474.97 mmol), and THF (1600 mL) at room temperature. To the above mixture, 13 (93.35 g, 431.79 mmol) and DIAD (96.04 g, 474.97 mmol) were added dropwise over 2 h at −10 °C. The resulting mixture was stirred at room temperature for an additional 3 h. The reaction was quenched by adding water / ice (1 L) at 0 °C. The resulting mixture was extracted with EtOAc (2 × 1 L). The combined organic layers were washed with brine (1 × 1 L) and dried over anhydrous Na2SO4. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by flash silica gel chromatography eluting with PE / EA (1:1) to give 14 (80 g, 75%).

[0184] [ka]

[0185] To a 2 L three-necked round-bottom flask, 14 (80 g, 161.74 mmol) and THF (800 mL) were added at room temperature. To the above mixture, hydrazine hydrate (12.15 g, 242.61 mmol) was added dropwise over 30 min at 0 °C. The resulting mixture was stirred at room temperature for an additional 3 h. The resulting mixture was concentrated under reduced pressure. The residue was purified by flash silica gel chromatography, eluting with PE / EA (1:1) to give 15 (55 g, 87%).

[0186] [ka]

[0187] To a 500 mL three-necked round-bottom flask, 15 (55 g, 140.84 mmol) and THF (550 mL) were added at room temperature. To the above mixture, TBAF (36.82 g, 140.84 mmol) was added dropwise over 0.5 h at 0 °C. The resulting mixture was stirred at room temperature for an additional 3 h. The resulting mixture was extracted with CHCl (2 × 1 L). The combined organic layers were washed with brine (1 × 1 L) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure to give 16 (40 g, crude), which was used in the next step without further purification.

[0188] To a 1 L three-necked round-bottom flask, 16 (40 g, 156.09 mmol), imidazole (31.42 g, 468.27 mmol), and THF (400 mL) were added at room temperature. To the above mixture, tert-butyl(chloro)diphenylsilane (85.81 g, 312.18 mmol) was added dropwise over 1 h at 0 °C. The resulting mixture was stirred at room temperature for an additional 3 h. The resulting mixture was extracted with EtOAc (2 × 400 mL). The combined organic layers were washed with brine (1 × 400 mL) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by flash silica gel chromatography eluting with PE / EA (1:1) to give 17 (52 g, 67%).

[0189] [ka]

[0190] To a 1 L three-necked round-bottom flask, 17 (52 g, 105.12 mmol) and methanol (500 mL) were added at room temperature. To the above mixture, NaOH (2 M, 100 mL) was added dropwise over 1 h at 0 °C. The resulting mixture was stirred at room temperature for an additional 3 h. The resulting mixture was extracted with EtOAc (2 × 200 mL). The combined organic layers were washed with brine (1 × 200 mL) and dried over anhydrous NaSO. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by trituration with MeOH (100 mL), and the solid was collected by filtration to give 18 (40.2 g, 84%).

[0191] [ka]

[0192] Under a N atmosphere, 18 (2.4 g, 5 mmol) was dissolved in DCM (75 mL). DMP (3.0 g, 7 mmol) was added at 0 °C, and the mixture was stirred at room temperature for an additional 2 h. To the mixture was added a 50 mL mixture of 30% aqueous NaSO and saturated aqueous NaHCO (1:1), and the aqueous layer was extracted with EtOAc (3x). The combined organic layers were dried over NaSO and concentrated in vacuo to give 19 as a crude product, which was used in the next step without further purification.

[0193] Under a N2 atmosphere, NaH (60% dispersion in mineral oil, 440 mg, 18 mmol) was suspended in THF (10 mL) and the mixture was cooled to -40 °C. Tetraethyl methylene diphosphonate (3.0 mL, 12 mmol) was added, and the mixture was stirred at -40 °C for 30 min. To this mixture, a solution of 19 (2.3 g, 5 mmol) in THF (25 mL) was added dropwise over 10 min at -40 °C, and the mixture was stirred for 100 min while warming to -10 °C. The crude reaction mixture was poured into water, and the product was extracted into ethyl acetate (3x). The organic layer was dried over anhydrous Na2SO4 and concentrated in vacuo. The crude product was purified by flash silica gel chromatography (heptane / EtOAc:EtOH (3:1), gradient 100:0 to 0:100) to give 20 (2.1 g, 35%) as an inseparable mixture with tetraethyl methylene diphosphonate.

[0194] [ka]

[0195] Under a N2 atmosphere, 20 (2.1 g, 1.8 mmol) was dissolved in THF (31 mL), TBAF (1 M in THF, 2.3 mL, 2.3 mmol) was added at room temperature, and the mixture was stirred for 16 h. The solvent was removed in vacuo, and the crude material was purified by flash silica gel chromatography (DCM / MeOH, gradient 100:0 to 94:6) to give 21a and 21b (562 mg, 91%) as racemates. Purification was carried out via preparative SFC (stationary phase: Chiralpak Diacel AD 20 × 250 mm, mobile phase: CO2, EtOH + 0.4 iPrNH2). 21a and 21b were each purified again by preparative SFC (stationary phase: Torus Diol 30 × 150 mm, mobile phase: CO2, MeOH + 0.4 iPrNH2) to give 21a (192 mg, 31%). 21b was further purified by preparative SFC (stationary phase: Chiralpak Diacel AD 20 x 250 mm, mobile phase: CO2, EtOH + 0.4 iPrNH2) to give 21b (163 mg, 27%).

[0196] [ka]

[0197] Under a N atmosphere, 7 (192 mg, 0.55 mmol) and 4,5-dicyanoimidazole (DCI, 56 mg, 0.47 mmol) were dissolved in dry DCM (3 mL). 2-Cyanoethyl-N,N,N',N'-tetraisopropylphosphorosdiamidite (0.23 mL, 0.72 mmol) was added, and the mixture was stirred at room temperature for 16 h. The mixture was concentrated in vacuo, and the crude material was purified by flash silica gel chromatography (0.15% TEA in heptane with 0.15% TEA / EtOAc, 100:0 to 0:100 gradient, then DCM / MeOH, 100:0 to 95:5 gradient) to give 22a (205 mg, 68%). 1 H NMR(400MHz,acetonitrile-d3)δ ppm 1.14-1.22(m,12H),1.23-1.30(m,6H),1.78-1.90(m,2H),2.50-2.65(m,2H),2.65-2.72(m,2H),3.56-3.78(m,4H),3.78-3. 94(m,2H),3.94-4.10(m,5H),5.49-5.57(m,1H),5.72-5.87(m,1H),6.59-6.80(m,1H),7.27-7.37(m,1H),8.79-9.00(m,1H). 31 P NMR (162 MHz, acetonitrile-d3) δ ppm 16.9, 17.2, 146.8, 147.8. LCMS: Method A, Rt: 1.00, 545.2 [MH] - ,1.02,545.2[MH] -

[0198] [ka]

[0199] Under a N atmosphere, 21b (163 mg, 0.47 mmol) and 4,5-dicyanoimidazole (DCI, 47 mg, 0.40 mmol) were dissolved in dry DCM (2.6 mL). 2-Cyanoethyl-N,N,N',N'-tetraisopropylphosphorosdiamidite (0.19 mL, 0.61 mmol) was added, and the mixture was stirred at room temperature for 16 h. The mixture was concentrated in vacuo, and the crude material was purified by flash silica gel chromatography (0.15% TEA in heptane with 0.15% TEA in EtOAc, 100:0 to 0:100 gradient, then DCM / MeOH, 100:0 to 95:5 gradient) to give 22a (196 mg, 76%). 1 H NMR(400MHz,acetonitrile-d3)δ ppm 1.16-1.22(m,12H),1.23-1.30(m,6H),1.79-1.91(m,2H),2.48-2.62(m,2H),2.64-2.71(m,2H),3.56-3.76(m,4H),3.79-3. 94(m,2H),3.94-4.09(m,5H),5.50-5.58(m,1H),5.71-5.85(m,1H),6.58-6.79(m,1H),7.28-7.39(m,1H),8.81-9.03(m,1H). 31 P NMR (162 MHz, acetonitrile-d3) δ ppm 16.9, 17.2, 146.8, 147.8. LCMS: Method A, Rt: 0.96, 545.3 [MH] - ,0.99,545.3[MH] -

[0200] [ka]

[0201] To a solution of compound 23 (9.00 g, 32.8 mmol) in pyridine (90.0 mL) was added AcO (3.1 mL, 32.8 mmol) at 10-25 °C. The mixture was stirred at 0 °C for 2 h. The reaction mixture was concentrated under reduced pressure to remove the solvent. The residue was purified by flash silica gel chromatography (PE / EtOAc, 100:0 to 0:100 gradient) to give compound 13 (18.0 g, 86% yield).

[0202] [ka]

[0203] To a solution of compound 24 (18.0 g, 56.9 mmol) in DCM (100 mL) was added imidazole (11.6 g, 171 mmol). Then, TBSCl (20.9 mL, 170 mmol) in 25.0 mL of dichloromethane was slowly added at 25 °C. The mixture was stirred at 25 °C for 12 h. The reaction mixture was quenched by adding 400 mL of HO at 0 °C and then extracted with 600 mL of ethyl acetate (200 mL × 3). The combined organic layers were washed with 200 mL of brine, dried over NaSO, filtered, and concentrated under reduced pressure. The crude product was purified by flash silica gel chromatography (PE / EtOAc, gradient 100:0 to 80:20) to give compound 25 (21.0 g, 85% yield).

[0204] [ka]

[0205] To a solution of compound 25 (21.0 g, 48.7 mmol) in MeOH (150 mL) was added K2CO3 (13.5 g, 97.5 mmol). The mixture was stirred at 25 °C for 0.5 h. The reaction mixture was quenched by adding 350 mL of HO at 0 °C and then extracted with 600 mL of ethyl acetate (200 mL × 3). The combined organic layers were washed with 200 mL of brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified by flash silica gel chromatography (PE / EtOAc, gradient 100:0 to 0:100) to give compound 25 (21.0 g, 85% yield). The crude product was further purified by reversed-phase SFC (column: DAICEL CHIRALPAK AS (250 mm × 50 mm, 10 μm); mobile phase: [Neu-ETOH]; B%: 20% to 20%, min) to give 26 (14.5 g, 84%).

[0206] [ka]

[0207] Under a N atmosphere, 26 (1.9 g, 5.0 mmol) was dissolved in DCM (50 mL). DMP (3.3 g, 7.8 mmol) was added, and the mixture was stirred at room temperature for 3 h. To the mixture was added a 50 mL mixture of 30% aqueous NaSO and saturated aqueous NaHCO (1:1), and the aqueous layer was extracted with EtOAc (3x). The combined organic layers were dried over NaSO and concentrated in vacuo to give 27 (2.5 g) as a crude product, which was used in the next step without further purification.

[0208] Under a N2 atmosphere, NaH (60% dispersion in mineral oil, 588 mg, 15 mmol) was suspended in THF (17 ml), and the mixture was cooled to -78 °C. A solution of 5 (7.7 g, 14.5 mmol) in THF (9 ml) was added, and the mixture was stirred at -78 °C for 60 min. To this mixture, a solution of 27 (3.0 g, 6 mmol) in THF (17 ml) was added dropwise over 15 min at -78 °C, and stirring was continued for 1 h at the same temperature. The mixture was warmed to 0 °C and stirred for 1 h, followed by stirring at room temperature for an additional 1 h. The crude reaction mixture was poured into 50 ml of saturated aqueous NH4Cl, and the product was extracted into 50 ml of ethyl acetate (3x). The organic layer was washed with brine and dried over anhydrous Na2SO4. The solution was then concentrated under reduced pressure and the residue was purified by flash silica gel chromatography (heptane: EtOAc, gradient from 100:0 to 0:100) to give compound 28 (1.4 g, 40%).

[0209] [ka]

[0210] To a mixture of 28 (608 mg, 0.9 mmol) and distilled water (15 mL) was added formic acid (15 mL). The reaction was stirred at room temperature for 20 h. The solvent was removed in vacuo, and the crude material was purified by flash silica gel chromatography (DCM / MeOH, gradient 100:0 to 95:5) to give 29 (402 mg, 79%).

[0211] [ka]

[0212] Under a N2 atmosphere, 7 (402 mg, 0.7 mmol) and 4,5-dicyanoimidazole (DCI, 70 mg, 0.6 mmol) were dissolved in dry DCM (3.9 mL). 2-Cyanoethyl-N,N,N',N'-tetraisopropylphosphorosdiamidite (0.29 mL, 0.9 mmol) was added, and the mixture was stirred at room temperature for 16 h. The organic layer was poured into water and washed with water (2x) and brine (1x). The organic layer was dried over Na2SO4 and concentrated in vacuo. The crude product was purified by flash silica gel chromatography (0.15% TEA in heptane with 0.15% TEA / EtOAc, gradient 100:0 to 0:100) to give 30 (163 mg, 30%) and another fraction of 30 (279 mg, 36%, 70% purity). 1 H NMR (400 MHz, acetonitrile-d3) δ ppm 1.15-1.22 (m, 30H), 2.63-2.71 (m, 2H), 3.43-3.49 (m, 3H), 3.56-3.68 (m, 2H), 3.68-3.79 (m, 1H), 3.79-3.88 (m, 1H), 3.92-4.00 (m, 1H), 4.09-4.22 (m, 1H), 4.29-4.39 (m, 1H), 5.57-5.71 (m, 5H), 5.99-6.15 (m, 2H), 6.79-7.00 (m, 1H), 7.79-7.85 (m, 1H), 8.82-9.07 (m, 1H). 31 P NMR (162 MHz, acetonitrile-d3) δ ppm 15.7, 15.9, 149.9, 150.3. LCMS: Method A, Rt: 1.23, 779.4 [M+H] + ,1.24,779.4[M+H] + .

[0213] Example 4 - Example of the synthesis of an unlocked vinyl phosphonate

[0214] [ka]

[0215] [Table 3]

[0216] CPG (25 umol, 30 mg) carrying a synthetic n-1 oligonucleotide with 5'-DMTr was placed in a 1 mL syringe equipped with a filter and cap.

[0217] Step 1. A syringe was filled with 3% dichloroacetic acid in DCM and kept at ambient temperature for 20 minutes. The solvent was removed and the CPG was washed six times with 0.6 ml of acetonitrile and three times with dry DCM, then dried in vacuo for 30 minutes.

[0218] Step 2. A syringe was filled with 200 μL of a 0.1 M solution of phosphonate amidite in dry acetonitrile and 200 μL of a 0.25 M solution of 5-(ethylthio)-1H-tetrazole in acetonitrile. The syringe was tightly closed and gently shaken at ambient temperature for 40 minutes. The solvent was removed, and the procedure was repeated twice. The solvent was removed, and the CPG was washed six times with 0.6 ml of acetonitrile. A 0.05 M solution of iodine in 9:1 pyridine / water (v:v) was added, held for 15 minutes, and repeated twice. The CPG was washed six times with 0.6 ml of acetonitrile and three times with dry DCM, then dried in vacuo for 30 minutes. An aliquot of CPG (2 mg) was taken and treated with AMA at 60°C for 10 minutes, and the MW of the resulting oligo was confirmed by LCMS. If the coupling did not proceed to completion, step 2 was repeated.

[0219] Step 3. The dried CPG in the syringe was treated with 250 μL of a 3.5% solution of trimethylsilyl iodide in 50:1 acetonitrile / pyridine (v / v) at ambient temperature for 20 minutes. This treatment was repeated three times. The solvent was removed, and the CPG was washed six times with 0.6 ml of acetonitrile, then treated with a solution of 4% mercaptoethanol in 1:1 pyridine / triethylamine (v:v) at room temperature for 20 minutes. The solvent was removed, and the CPG was washed six times with 0.6 ml of acetonitrile and three times with dry DCM, then dried in vacuo for 30 minutes. An aliquot of CPG (2 mg) was taken and treated with AMA at 60°C for 10 minutes, and the MW of the resulting oligo was confirmed by LCMS. If deprotection had not proceeded to completion, step 3 was repeated.

[0220] Step 4. The CPG in the syringe was treated with 200 μL of AMA for 3 hours and filtered. The solid support was washed five times with 250 μL of water. The filtrate and washes were combined and diluted up to 10 mL, and the target compound was isolated by ion exchange chromatography. The column was a GE Source 15Q 250 × 10 mm. Buffer A was 20 mM sodium phosphate in acetonitrile / water 9:1 (v:v), and buffer B was 1.8 M sodium borate in buffer A (pH 7.5). A gradient of 5% to 60% B over 10 column volumes was used, and the target compound was eluted at 25–35% B. The resulting oligonucleotide was desalted and used for annealing.

[0221] Step 5. Annealing was achieved by mixing equimolar amounts of the sense and antisense strands. The resulting siRNA was analyzed by LCMS under denaturing conditions at 80°C.

[0222] [Table 4]

[0223] [Table 5]

[0224] [Table 6]

[0225] The above table shows the percent HTRA remaining after 3 days in vitro (n=3 samples) when varying concentrations of oligonucleotides with the specified phosphate attached were used, where oligonucleotides 1 and 2 were different and the oligonucleotides in the remaining samples were identical except for the specified phosphate.

[0226] [Table 7]

[0227] The above table shows the KD results of the novel stable phosphates at 2 and 4 weeks after intravitreal injection. The oligonucleotides in the samples were identical except for the specified phosphate.

[0228] Additional embodiments include: 1. Formula (Ia) or (Ib):

[0229] [ka] A compound represented by the formula: X is a 3- to 5-membered cycloalkyl, -CHCH-, a 3- to 5-membered heterocycle, or -CHR 3 CHR 3 - selected from Y is selected from O or NR'; R' is a counterion, H, or a protecting group; Z is selected from H, a counterion, an activating group, and an oligonucleotide; A is O, S, and CR 4 R 4 is selected from B is a nucleobase, each R is independently selected from an oligonucleotide, a counterion, H, and a protecting group, e.g., C1-C5 alkyl and POM or C1-C5 alkyl; Each R 1 and R 2 is independently selected from H, F, OH, and optionally substituted O-alkyl, with the proviso that R 1 and R 2 However, each one is not H, Each R 3 are independently selected from C1-C3 alkyl; Each R 4 is independently selected from H, F, and C1-C5 alkyl; with the proviso that when A is O, X is not -CHCH-, and when X is cyclopropyl, at least one of A or Y is not O. 2. The compound of formula (Ia)

[0230] [ka] The compound of embodiment 1, represented by: 3. The compound of embodiment 1 or 2, wherein X is cyclobutyl. 4. Cyclobutyl is

[0231] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. 5. X is -CHR 3 CHR 3 - and R 3 The compound of embodiment 1 or 2, wherein is methylene. 6. X is

[0232] [ka] wherein the dashed lines represent points of attachment to adjacent atoms. 7. X is

[0233] [ka] The compound of embodiment 1 or 2, wherein the 3-5 membered heterocycle is selected from the group consisting of: 8. The compound of any one of embodiments 1-7, wherein Y is O. 9. The compound of any one of embodiments 1-8, wherein Z is an activating group. 10. The activating group is

[0234] [ka] 10. The compound of embodiment 9, wherein the compound is represented by the formula: 11. The compound of any one of embodiments 1 to 8, wherein Z is an oligonucleotide. 12. The compound of embodiment 11, wherein the oligonucleotide is the antisense strand of an RNA, preferably the antisense strand of an siRNA. 13. The compound of embodiment 11 or 12, wherein the 5' end of the oligonucleotide is linked to Y. 14. The compound of any one of embodiments 1-13, wherein A is O. 15. The compound of any one of embodiments 1-13, wherein A is CH2 or CHF. 16. The compound of embodiment 15, wherein X is -CHCH-. 17. The compound of any one of embodiments 1-16, wherein B is uracil. 18. R 1 is H and R 2 The compound of any one of embodiments 1-17, wherein is OMe, OEt, MOE, or F. 19. The compound of any one of embodiments 1-18, wherein R is a protecting group, e.g., POM, Et, and Z is an activating group. 20. The compound of any one of embodiments 1-18, wherein R is H and Z is an oligonucleotide.

[0235] As will be understood by those skilled in the art, for any and all purposes, and in view of providing a specifically written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of those subranges. Any recited range can be readily recognized as fully descriptive and allowing the same range to be broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be easily broken down into a lower third, middle third, upper third, etc. As will be understood by those skilled in the art, all terms such as "up to," "at least," "greater than," "less than," etc., are inclusive of the recited numbers and refer to ranges that can subsequently be broken down into subranges as discussed above. Finally, as will be understood by those skilled in the art, a range includes each individual member.

[0236] All publications, patent applications, issued patents, and other documents mentioned herein are incorporated by reference herein as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions contained in the text incorporated by reference are excluded to the extent they conflict with definitions in this disclosure.

[0237] Other embodiments are set forth in the following claims.

Claims

1. Formula (Ia) or (Ib): 【Chemical 1】 A compound represented by the formula: X is a 3- to 5-membered cycloalkyl, —CHCH—, a 3- to 5-membered heterocycle, or —CHR ３ CHR ３ - is selected from, Y is selected from O or NR'; R' is a counterion, H, or a protecting group; Z is selected from H, a counterion, an activating group, and an oligonucleotide; A and the connecting dashed line are optional, and if present, A is O, S, and CR. ４ R ４ is selected from B is a nucleobase; Each R independently represents an oligonucleotide, a counterion, H, and a protecting group, e.g., C １ ~C ５ Alkyl and POM or C １ ~C ５ alkyl, Each R １ and R ２ is independently selected from H, F, OH, and optionally substituted O-alkyl, with the proviso that X is a 3- to 5-membered cycloalkyl, —CHCH—, a 3- to 5-membered heterocycle, and —CHR ３ CHR ３ -, R １ and R ２ are not H or R １ and R ２ forms an optionally substituted oxetine, Each R ３ But independently, C １ ~C ３ alkyl, Each R ４ are independently H, F, and C １ ~C ５ alkyl, R ５ and R ６ One of the two is XP(O)(OR) ２ and the other is H, With the proviso that when A is O, X is not —CHCH—, and when X is cyclopropyl, at least one of A or Y is not O.

2. the compound is a compound of formula (Ia), 【Chemistry 2】 The compound according to claim 1, represented by:

3. 3. The compound of claim 1 or 2, wherein X is cyclobutyl.

4. The cyclobutyl 【Chemistry 3】 4. The compound of claim 3, wherein the compound is represented by the formula: wherein the dashed lines represent points of attachment to adjacent atoms.

5. X is -CHR ３ CHR ３ - and R ３ The compound according to claim 1 or 2, wherein is methylene.

6. X is, 【Chemistry 4】 6. The compound of claim 5, wherein the compound is selected from the following formula:

7. X is, 【Chemistry 5】 The compound according to claim 1 or 2, wherein the broken line represents the point of attachment to the adjacent atom.

8. The compounds of formula (Ia) and (Ib) 【Chemistry 6】 The compound according to claim 1, represented by:

9. R ２ 3. The compound of claim 1 or 2, wherein is an optionally substituted oxetine.

10. 10. The compound of claim 9, wherein X is -CHCH-.

11. The compound of any one of claims 1 to 10, wherein Y is O.

12. The compound of any one of claims 1 to 11, wherein Z is an activating group.

13. The activating group is 【Chemistry 7】 13. The compound of claim 12, wherein the compound is represented by the formula: wherein the dashed lines represent points of attachment to adjacent atoms.

14. The compound of any one of claims 1 to 11, wherein Z is an oligonucleotide.

15. The compound of claim 14, wherein the oligonucleotide is the antisense strand of an RNA, preferably the antisense strand of an siRNA.

16. The compound of claim 14 or 15, wherein the 5' end of the oligonucleotide is linked to Y.

17. The compound of any one of claims 1 to 16, wherein A is O.

18. A is CH ２ or CHF.

19. 19. The compound of claim 18, wherein X is —CHCH—.

20. 20. The compound of any one of claims 1 to 19, wherein B is uracil or thymine.

21. R １ is H and R ２ The compound of any one of claims 1 to 17, wherein is OMe, OEt, MOE, or F.

22. 22. The compound of any one of claims 1 to 21, wherein R is a protecting group, e.g., POM, Et, and Z is an activating group.

23. 22. The compound of any one of claims 1 to 21, wherein R is H and Z is an oligonucleotide.

24. [Table 1] or a compound of the Table, wherein the nucleobase is thymine or cytosine.

25. R ２ The compound of claim 24, wherein is -OMe.

26. 26. The compound of claim 24 or 25, wherein R is Et and Z is an activating group.

27. 26. The compound of claim 24 or 25, wherein R is H or a counterion and Z is an oligonucleotide.

Images