Preparation of lipidated peptides

Abstract

Lipid modifications can be used to improve the pharmacokinetic profile of therapeutic peptides. Provided herein are compounds and methods useful in the preparation of peptides comprising one or more lipidated lysine resides. The compounds provided herein can be used in the preparation of lipidated peptides via peptide synthesis (e.g., solid phase peptide synthesis (SPPS) or liquid phase peptide synthesis (LPPS)).

Description

Attorney Docket No. METS-031 / 01WO 350242-2279PREPARATION OF LIPIDATED PEPTIDESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U. S. Provisional Application No. 63 / 738,028, filed on December 23, 2024, the contents of which are incorporated herein by reference in their entirety.REFERENCE TO AN ELECTRONIC SEQUENCE LISTING

[0002] The contents of the electronic sequence listing (METS_031_01WO_SeqList_ST26.xml; Size: 2,712 bytes; and Date of Creation: December 19, 2025) are herein incorporated by reference in their entirety.BACKGROUND

[0003] Peptide lipidation is a promising strategy to improve pharmacokinetic and pharmacodynamic profiles of therapeutic peptides. See, e.g., Kowalczyk et al. “Peptide Lipidation - A Synthetic Strategy to Afford Peptide Based Therapeutics” Adv Exp Med Biol.2017 Oct 29; 1030:185-227. For instance, current standards for injectable peptides for weight loss and metabolic disorder management, including liraglutide, semaglutide, and tirzepatide, include lipidated amino acids (e.g., lipidated lysine residues). Because efficient and scalable methods for producing peptides remains a challenge, new compounds and methods are needed for the synthesis of peptides, including lipidated peptides.SUMMARY

[0004] Provided herein are compounds and methods useful in the preparation of peptides comprising one or more lipidated lysine resides. The compounds provided herein can be used in the preparation of lipidated peptides via peptide synthesis (e.g., solid phase peptide synthesis (SPPS) or liquid phase peptide synthesis (LPPS)).

[0005] In one aspect, provided herein are compounds of Formula (I):Attorney Docket No. METS-031 / 01WO 350242-2279and salts thereof, wherein:RNPis hydrogen or a nitrogen protecting group;ROPis hydrogen, C1-6 alkyl, an oxygen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS); andROP1and ROP2are each independently hydrogen, Ci-6 alkyl, or an oxygen protecting group.

[0006] In certain embodiments, the compound is Compound (A):or a salt thereof.

[0007] In certain embodiments, the compound is Compound (B):or a salt thereof.

[0008] In some embodiments, ROPis a resin for solid phase peptide synthesis (SPPS) or a tag for liquid phase peptide synthesis (LPPS). In certain embodiments, the compound is any one of Compounds (C)-(F):Attorney Docket No. METS-031 / 01 WO 350242-2279(E),Attorney Docket No. METS-031 / 01WO 350242-2279or a salt thereof, wherein P is a polymer.

[0009] Also provided herein are compounds useful in preparing lipidated peptides comprising an amidated C-terminus. Therefore, in another aspect, provided herein are compounds of Formula (III):and salts thereof, wherein:RNPis hydrogen or a nitrogen protecting group;RNP1is hydrogen, a nitrogen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS); andROP1and ROP2are each independently hydrogen, Ci-6 alkyl, or an oxygen protecting group.

[0010] Also provided herein are methods of synthesizing peptides (e.g., via SPPS or LPPS) employing the compounds provided herein. The compounds and methods provided herein can be used to produce lipidated peptides with improved efficiency and / or scalability.DEFINITIONS

[0011] The following definitions are general terms used throughout the present disclosure.

[0012] Definitions of specific functional groups and chemical terms are described in more detail below. The chemical elements are identified in accordance with the Periodic Table of theAttorney Docket No. METS-031 / 01WO 350242-2279Elements, CAS version, Handbook of Chemistry and Physics, 75thEd., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and reactivity, are described in Thomas Sorrell, Organic Chemistry, University Science Books, Sausalito, 1999; Michael B. Smith, March’s Advanced Organic Chemistry, 7thEdition, John Wiley & Sons, Inc., New York, 2013; Richard C. Larock, Comprehensive Organic Transformations, John Wiley & Sons, Inc., New York, 2018; and Carruthers, Some Modern Methods of Organic Synthesis, 3rdEdition, Cambridge University Press, Cambridge, 1987.

[0013] Compounds described herein can comprise one or more asymmetric centers, and thus can exist in various stereoisomeric forms, e.g., enantiomers and / or diastereomers. For example, the compounds described herein can be in the form of an individual enantiomer, diastereomer or geometric isomer, or can be in the form of a mixture of stereoisomers, including racemic mixtures and mixtures enriched in one or more stereoisomer. Isomers can be isolated from mixtures by methods known to those skilled in the art, including chiral high pressure liquid chromatography (HPLC) and the formation and crystallization of chiral salts; or preferred isomers can be prepared by asymmetric syntheses. See, for example, Jacques et al., Enantiomers, Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen et al., Tetrahedron 33:2725 (1977); Eliel, E. L. Stereochemistry of Carbon Compounds (McGraw-Hill, NY, 1962); and Wilen, S. H., Tables of Resolving Agents and Optical Resolutions p. 268 (E. L. Eliel, Ed., Univ, of Notre Dame Press, Notre Dame, IN 1972). The invention additionally encompasses compounds as individual isomers substantially free of other isomers, and alternatively, as mixtures of various isomers.

[0014] When a range of values (“range”) is listed, it encompasses each value and sub-range within the range. A range is inclusive of the values at the two ends of the range unless otherwise provided. For example “Ci-6 alkyl” encompasses, Ci, C2, C3, C4, Cs, Ce, C1-6, C1-5, C1-4, C1-3, C1-2, C2-6, C2-5, C2-4, C2-3, C3-6, C3-5, C3-4, C4-6, C4-5, and C5-6 alkyl.

[0015] Use of the phrase “at least one instance” refers to 1, 2, 3, 4, or more instances, but also encompasses a range, e.g., for example, from 1 to 4, from 1 to 3, from 1 to 2, from 2 to 4, from 2 to 3, or from 3 to 4 instances, inclusive.

[0016] The term “alkyl” refers to a radical of a straight-chain or branched saturated hydrocarbon group having from 1 to 20 carbon atoms (“C1-20 alkyl”) unless otherwise specified. In some embodiments, an alkyl group has 1 to 6 carbon atoms (“C1-6 alkyl”). Examples of C1-6 alkyl groups include methyl (Ci), ethyl (C2), propyl (C3) (e.g., w-propyl, isopropyl), butyl (C4) (e.g., / / -butyl, tert-butyl, ec-butyl, isobutyl), pentyl (Cs) (e.g., w-pentyl,Attorney Docket No. METS-031 / 01WO 350242-22793-pentanyl, amyl, neopentyl, 3-methyl-2-butanyl, tert-amyl), and hexyl (Ce) (e.g, / / -hexyl). Additional examples of alkyl groups include / / -heptyl (C7), / / -octyl (Cs), w-dodecyl (C12), and the like.

[0017] In certain embodiments, the substituent present on the nitrogen atom is a nitrogen protecting group (also referred to herein as an “amino protecting group”). Nitrogen protecting groups are well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rdedition, John Wiley & Sons, 1999, incorporated herein by reference.

[0018] For example, in certain embodiments, at least one nitrogen protecting group is an amide group (a moiety that includes the nitrogen atom to which the nitrogen protecting groups is directly attached). In certain such embodiments, each nitrogen protecting group, together with the nitrogen atom to which the nitrogen protecting group is attached, is independently selected from the group consisting of formamide, acetamide, chloroacetamide, trichloroacetamide, trifluoroacetamide, phenylacetamide, 3-phenylpropanamide, picolinamide, 3-pyridylcarboxamide, A-benzoylphenylalanyl derivatives, benzamide, / / -phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide, acetoacetamide, (P -dithiobenzyloxyacylamino)acetamide, 3-( / / -hydroxyphenyl)propanamide, 3-(o-nitrophenyl)propanamide, 2-methyl-2-(o-nitrophenoxy)propanamide, 2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide, 3-methyl-3-nitrobutanamide, o-nitrocinnamide, A-acetylmethionine derivatives, o-nitrobenzamide, and o-(b enzoy 1 oxy methy l)b enzami de.

[0019] In certain embodiments, at least one nitrogen protecting group is a carbamate group (a moiety that includes the nitrogen atom to which the nitrogen protecting group is directly attached). In certain such embodiments, each nitrogen protecting group, together with the nitrogen atom to which the nitrogen protecting group is attached, is independently selected from the group consisting of methyl carbamate, ethyl carbamate, 9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethyl carbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate, 2,7-di- / -butyl-[9-(l 0, 10-dioxo- 10, 10, 10, 10-tetrahydrothioxanthyl)]methyl carbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc), 2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate (Teoc), 2-phenylethyl carbamate (hZ), l-(l-adamantyl)-l-m ethylethyl carbamate (Adpoc), l,l-dimethyl-2-haloethyl carbamate, l,l-dimethyl-2,2-dibromoethyl carbamate (DB- / -BOC), l,l-dimethyl-2, 2, 2 -tri chloroethyl carbamate (TCBOC), 1 -methyl- l-(4-biphenylyl)ethyl carbamate (Bpoc), l-(3,5-di-tebutylphenyl)-l-methylethyl carbamate (A-Bumeoc), 2-(2 - and 40-pyridyl)ethyl carbamate (Pyoc), 2-(N, N-Attorney Docket No. METS-031 / 01WO 350242-2279dicyclohexylcarboxamido)ethyl carbamate, / -butyl carbamate (BOC or Boc), 1-adamantyl carbamate (Adoc), vinyl carbamate (Voc), allyl carbamate (Alloc), 1 -isopropylallyl carbamate (Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc), 8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithio carbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz), / ?-nitobenzyl carbamate, / ?-bromobenzyl carbamate, p-chlorobenzyl carbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzyl carbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate, 2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate, 2-(p-toluenesulfonyl)ethyl carbamate, [2-(l,3-dithianyl)]methyl carbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc), 2,4-dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate (Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc), l,l-dimethyl-2-cyanoethyl carbamate, m-chloro- -acyloxybenzyl carbamate, -(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate, 2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenyl carbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate, 3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methyl carbamate, / -amyl carbamate, 5-benzyl thiocarbamate, -cyanobenzyl carbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentyl carbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate, 2,2-dimethoxyacylvinyl carbamate, o-(N, N-dimethylcarboxamido)benzyl carbamate, 1,1 -di methyl -3 -(A, A-di methyl carb oxami do)propyl carbamate, 1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate, 2-furanylmethyl carbamate, 2-iodoethyl carbamate, isoborynl carbamate, isobutyl carbamate, isonicotinyl carbamate, p-(p ’-methoxyphenylazo)benzyl carbamate, 1 -methylcyclobutyl carbamate, 1-methylcyclohexyl carbamate, 1 -methyl- 1 -cyclopropylmethyl carbamate, l-methyl-l-(3,5-dimethoxyphenyl)ethyl carbamate, 1 -methyl- l-(p-phenylazophenyl)ethyl carbamate, 1-m ethyl- 1 -phenylethyl carbamate, 1 -methyl- l-(4-pyridyl)ethyl carbamate, phenyl carbamate, -(phenylazo)benzyl carbamate, 2,4,6-tri- / -butylphenyl carbamate, 4-(trimethylammonium)benzyl carbamate, and 2,4,6-trimethylbenzyl carbamate.

[0020] In certain embodiments, at least one nitrogen protecting group is a sulfonamide group (a moiety that includes the nitrogen atom to which the nitrogen protecting group is directly attached). In certain such embodiments, each nitrogen protecting group, together with the nitrogen atom to which the nitrogen protecting group is attached, is independently selected from the group consisting of -toluenesulfonamide (Ts), benzenesulfonamide, 2,3,6-trimethyl-4-methoxybenzenesulfonamide (Mtr), 2,4,6-trimethoxybenzenesulfonamide (Mtb), 2,6-dimethyl-4-methoxybenzenesulfonamide (Pme), 2,3,5,6-tetramethyl-4-Attorney Docket No. METS-031 / 01WO 350242-2279methoxybenzenesulfonamide (Mte), 4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide (Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds), 2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide (Ms), P-trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide, 4-(4',8'-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS), benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

[0021] In certain embodiments, each nitrogen protecting group, together with the nitrogen atom to which the nitrogen protecting group is attached, is independently selected from the group consisting of phenothiazinyl-(10)-acyl derivatives, N ’- -toluenesulfonylaminoacyl derivatives, N ’-phenylaminothioacyl derivatives, M-benzoyl phenyl alanyl derivatives, N-acetylmethionine derivatives, 4,5-diphenyl-3-oxazolin-2-one, M-phthalimide, N-dithiasuccinimide (Dts), N-2, 3 -diphenylmal eimide, M2, 5 -di methyl pyrrole, Ml, 1,4,4-tetramethyldisilylazacyclopentane adduct (STABASE), 5-substituted l,3-dimethyl-l,3,5-triazacyclohexan-2-one, 5-substituted l,3-dibenzyl-l,3,5-triazacyclohexan-2-one, 1-substituted 3,5-dinitro-4-pyridone, M-methylamine, M-allylamine, M-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3 -acetoxypropylamine, M-(l-isopropyl-4-nitro-2-oxo-3-pyroolin-3-yl)amine, quaternary ammonium salts, M-benzylamine, M-di(4-methoxyphenyl)methylamine, M-5-dibenzosuberylamine, M-triphenylmethylamine (Tr), M-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr), M-9-phenylfluorenylamine (PhF), M-2,7-dichloro-9-fluorenylmethyleneamine, M-ferrocenylmethylamino (Fem), M-2-picolylamino N’-oxide, N- 1,1 -dimethylthiomethyleneamine, M-benzylideneamine, M-p-methoxybenzylideneamine, M-diphenylmethyleneamine, M-[(2-pyridyl)mesityl]methyleneamine, M-(M’, M’-dimethylaminomethylene)amine, N-p-nitrobenzylideneamine, M-salicylideneamine, M-5-chlorosalicylideneamine, M-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine, M-cyclohexylideneamine, M-(5,5-dimethyl-3-oxo-l-cyclohexenyl)amine, M-borane derivatives, M-diphenylborinic acid derivatives, N-[phenyl(pentaacylchromium- or tungsten)acyl]amine, M-copper chelate, M-zinc chelate, N-nitroamine, M-nitrosoamine, amine M-oxide, diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt), diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzyl phosphoramidate, diphenyl phosphoramidate, benzenesulfenamide, o-nitrobenzenesulfenamide (Nps), 2,4-dinitrobenzenesulfenamide, pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide, triphenylmethylsulfenamide, and 3-nitropyridinesulfenamide (Npys). In some embodiments,Attorney Docket No. METS-031 / 01WO 350242-2279two instances of a nitrogen protecting group together with the nitrogen atoms to which the nitrogen protecting groups are attached are N, N" -isopropylidenediamine.

[0022] In certain embodiments, a nitrogen protecting group is benzyl (Bn or Bzl), tert-butyloxycarbonyl (BOC), carbobenzyl oxy (Cbz), 9-flurenylmethyloxycarbonyl (Fmoc), trifluoroacetyl, triphenylmethyl, acetyl (Ac), benzoyl (Bz), p-m ethoxybenzyl (PMB), 3,4-dimethoxybenzyl (DMPM), p-m ethoxyphenyl (PMP), 2, 2, 2-trichloroethyloxy carbonyl (Troc), triphenylmethyl (Tr), tosyl (Ts), brosyl (Bs), nosyl (Ns), mesyl (Ms), triflyl (Tf), or dansyl (Ds). In certain embodiments, at least one nitrogen protecting group is Bn, Boc, Cbz, Fmoc, trifluoroacetyl, triphenylmethyl, acetyl, or Ts. In certain embodiments, the nitrogen protecting group if Fmoc.

[0023] In certain embodiments, the substituent present on an oxygen atom is an oxygen protecting group (also referred to as “hydroxyl protecting group”). Oxygen protecting groups are well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rdedition, John Wiley & Sons, 1999, incorporated herein by reference.

[0024] In certain embodiments, each oxygen protecting group, together with the oxygen atom to which the oxygen protecting group is attached, is selected from the group consisting of methoxy, methoxylmethyl (MOM), methylthiomethyl (MTM), / -butylthiomethyl, (phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM), p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl ( -AOM), guaiacolmethyl (GUM), / -butoxymethyl, 4-pentenyloxymethyl (POM), siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR), tetrahydropyranyl (THP), 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1 -methoxy cyclohexyl, 4-methoxytetrahydropyranyl (MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranyl 5,5-dioxide, l-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl (CTMP), l,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1 -ethoxy ethyl, l-(2-chloroethoxy)ethyl, 1 -methyl- 1 -methoxy ethyl, 1 -methyl- 1-benzyloxy ethyl, 1 -methyl- l-benzyloxy-2-fluoroethyl, 2, 2, 2-tri chloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl, / -butyl, allyl, -chlorophenyl, / ?-methoxyphenyl, 2,4-dinitrophenyl, benzyl (Bn or Bzl), p- ethoxybenzyl (PMB), 3,4-dimethoxybenzyl, o-nitrobenzyl, / ?-nitrobenzyl, / ?-halobenzyl, 2,6-dichlorobenzyl, / ?-cyanobenzyl, / ?-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl A -oxi do, diphenylmethyl, p,p ’-dinitrobenzhydryl, 5-dibenzosuberyl, triphenylmethyl, a-naphthyldiphenylmethyl, p-Attorney Docket No. METS-031 / 01WO 350242-2279methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl, tri( / ?-methoxyphenyl)methyl, 4-(4’-bromophenacyloxyphenyl)diphenylmethyl, 4,4',4"-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4',4''-tris(levulinoyloxyphenyl)methyl, 4, 4', 4''-tris(benzoyloxyphenyl)methyl, 4,4'-Dimethoxy-3"'-[N-(imidazolylmethyl) ]trityl Ether (IDTr-OR), 4,4'-Dimethoxy-3"'-[N-(imidazolylethyl)carbamoyl]trityl Ether (lETr-OR), l,l-bis(4-m ethoxyphenyl)- l'-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, l,3-benzodithiolan-2-yl, benzisothiazolyl 5,5-dioxido, trimethyl silyl (TMS), triethylsilyl (TES), triisopropyl silyl (TIPS), dimethylisopropyl silyl (IPDMS), diethylisopropylsilyl (DEIPS), dimethylthexylsilyl, Ebutyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS), tribenzylsilyl, tri- / ?-xylylsilyl, triphenylsilyl, diphenylmethyl silyl (DPMS), Ebutylmethoxyphenyl silyl (TBMPS), formate, benzoylformate, acetate, chloroacetate, di chloroacetate, tri chloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, phenoxyacetate, -chlorophenoxyacetate, 3 -phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate (levulinoyldithioacetal), pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, -phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), methyl carbonate, 9-fluorenylmethyl carbonate (Fmoc), ethyl carbonate, 2,2,2-trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate (TMSEC), 2-(phenylsulfonyl) ethyl carbonate (Psec), 2-(triphenylphosphonio) ethyl carbonate (Peoc), isobutyl carbonate, vinyl carbonate, allyl carbonate, Ebutyl carbonate (BOC or Boc), p-nitrophenyl carbonate, benzyl carbonate, / ?-methoxybenzyl carbonate, 3,4-dimethoxybenzyl carbonate, o-nitrobenzyl carbonate, -nitrobenzyl carbonate, 5-benzyl thiocarbonate, 4-ethoxy-1-napththyl carbonate, methyl dithiocarbonate, 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate, 2-formylbenzenesulfonate, 2-(methylthiomethoxy)ethyl carbonate (MTMEC-OR), 4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4-(1,1, 3,3 -tetramethylbutyl)phenoxy acetate, 2,4-bi s( 1, 1 -dimethylpropyl)phenoxy acetate, chlorodiphenylacetate, isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate, o-(methoxyacyl)benzoate, a-naphthoate, nitrate, alkyl N, N, N N’-tetramethylphosphorodiamidate, alkyl A-phenyl carbamate, borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate, sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate (Ts).

[0025] In certain embodiments, an oxygen protecting group is silyl group. In certain embodiments, an oxygen protecting group is t-butyldiphenylsilyl (TBDPS), E butyldimethylsilyl (TBDMS), triisoproylsilyl (TIPS), triphenyl silyl (TPS), triethylsilyl (TES),Attorney Docket No. METS-031 / 01WO 350242-2279trimethyl silyl (TMS), triisopropylsiloxymethyl (TOM), acetyl (Ac), benzoyl (Bz), allyl carbonate, 2,2,2-trichloroethyl carbonate (Troc), 2-trimethylsilylethyl carbonate, methoxymethyl (MOM), 1-ethoxyethyl (EE), 2-methyoxy-2-propyl (MOP), 2,2,2-trichloroethoxyethyl, 2-methoxyethoxymethyl (MEM), 2-trimethylsilylethoxymethyl (SEM), methylthiomethyl (MTM), tetrahydropyranyl (THP), tetrahydrofuranyl (THF), p-methoxyphenyl (PMP), triphenylmethyl (Tr), methoxytrityl (MMT), dimethoxytrityl (DMT), allyl, / ?-methoxybenzyl (PMB), / -butyl, benzyl (Bn or Bzl), allyl, or pivaloyl (Piv).

[0026] In certain embodiments, at least one oxygen protecting group is a silyl group, MOM, THP, Z-Bu, Bn, allyl, acetyl, pivaloyl, or benzoyl. In some embodiments, at least one oxygen protecting group is TBDPS, TBDMS, TIPS, TES, TMS, MOM, THP, Z-Bu, Bn, allyl, acetyl, pivaloyl, or benzoyl. In certain embodiments, at least one oxygen protecting group is / -Bu.

[0027] The term “peptide” includes a polymer of amino acid residues linked together by peptide bonds. Typically, a peptide will be at least the length required by an amino acid sequence provided herein. Peptides provided herein can include natural amino acids and / or unnatural amino acids ( / .<., compounds that do not occur in nature but that can be incorporated into a peptide chain) in any combination. One or more of the amino acids in a peptide may be modified, for example, by the addition of a chemical entity such as a carbohydrate group, a hydroxyl group, a phosphate group, a farnesyl group, an isofarnesyl group, a fatty acid group, a lipid moiety, a linker for conjugation or functionalization, or other modification

[0028] Peptides described herein include those with an amidated C-terminus. “Amidated C-terminus” refers to peptides wherein the traditional C-terminus of the peptide (-C(=O)OH) is replaced with an amide (-C(=O)NH2).

[0029] A peptide provided herein can be of any length. In certain embodiments, a peptide is 50 amino acids or fewer in length. In certain embodiments, a peptide is 45 amino acids or fewer in length. In certain embodiments, a peptide is 41 amino acids or fewer in length. In certain embodiments, a peptide is 40 amino acids or fewer in length. In certain embodiments, a peptide is 35 amino acids or fewer in length. In certain embodiments, a peptide is 33 amino acids or fewer in length. In certain embodiments, a peptide is at least the length of an amino acid sequence provided herein. In certain embodiments, a peptide is the length of an amino acid sequence provided herein.

[0030] The term “amino acid” includes a molecule containing both an amino group and a carboxyl group. Unless otherwise indicated, an amino acid is an alpha-amino acid (a-amino acid), the generic structure of which is depicted below (wherein each R is independently H or an amino acid sidechain, / .<., an “a-sidechain”). Unless otherwise indicated, reference to aAttorney Docket No. METS-031 / 01WO 350242-2279particular amino acid implies the L-isomer of the amino acid. Each amino acid referred to herein may be denoted by a 1- to 4-letter code (e.g., L and Lys represent L-Lysine, etc.).R Ra amino acid

[0031] Suitable amino acids include, without limitation, natural a-amino acids such as D- and L-isomers of the 20 common naturally occurring a-amino acids found in peptides (e.g., A, R, N, C, D, Q, E, G, H, I, L, K, M, F, P, S, T, W, Y, V, as provided below), and unnatural a-amino acids.

[0032] Exemplary natural a-amino acids (with one-letter code provided in parentheses) include L-alanine (A), L-arginine (R), L-asparagine (N), L-aspartic acid (D), L-cysteine (C), L-glutamic acid (E), L-glutamine (Q), glycine (G), L-histidine (H), L-isoleucine (I), L-leucine (L), L-lysine (K), L-methionine (M), L-phenylalanine (F), L-proline (P), L-serine (S), L-threonine (T), L-tryptophan (W), L-tyrosine (Y), and L-valine (V).

[0033] Exemplary unnatural a-amino acids include, without limitation, D-arginine, D-asparagine, D-aspartic acid, D-cysteine, D-glutamic acid, D-glutamine, D-histidine, D-isoleucine, D-leucine, D-lysine, D-methionine, D-phenylalanine, D-proline, D-serine, D-threonine, D-tryptophan, D-tyrosine, D-valine, Di-vinyl, a-methyl-alanine (Aib), a-methyl-arginine, a-methyl-asparagine, a-methyl-aspartic acid, a-methyl-cysteine, a-methyl-glutamic acid, a-methyl-glutamine, a-methyl-histidine, a-methyl-isoleucine, a-methyl-leucine, a-methyl-lysine, a-methyl-methionine, a-methyl-phenylalanine, a-methyl-proline, a-methyl-serine, a-methyl-threonine, a-methyl-tryptophan, a-methyl-tyrosine, a-methyl-valine, norleucine, and terminally unsaturated a-amino acids. There are many known unnatural amino acids, any of which may be included in the peptides of the present disclosure. See for example, S. Hunt, The Non-Protein Amino Acids: In Chemistry and Biochemistry of the Amino Acids, edited by G. C. Barrett, Chapman and Hall, 1985.

[0034] Unnatural amino acids also include amino acids comprising a substituent (i.e., nonhydrogen group) on the peptide nitrogen. For example, any amino acid described herein can comprise a Ci-6 alkyl group on the peptide nitrogen (“N-alkyl”-amino acid). In certain embodiments, any amino acid described herein can comprise a methyl group on the peptide nitrogen (“N-methyl”-amino acid).

[0035] As used herein, the term “salt” includes any and all salts, and encompasses pharmaceutically acceptable salts. Salts include ionic compounds that result from theAttorney Docket No. METS-031 / 01WO 350242-2279neutralization reaction of an acid and a base. A salt is composed of one or more cations (positively charged ions) and one or more anions (negative ions) so that the salt is electrically neutral (without a net charge). Salts of the peptides of this invention include those derived from inorganic and organic acids and bases.

[0036] The term “pharmaceutically acceptable salt” includes those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, and the like, and are commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, Berge et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66, 1-19, incorporated herein by reference. Pharmaceutically acceptable salts of the peptides of this invention include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids, such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid or with organic acids, such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid or by using other methods known in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3 -phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like. Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium, and N+(CI-4 alkyl)4 salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate, and aryl sulfonate.Attorney Docket No. METS-031 / 01WO 350242-2279DETAILED DESCRIPTION

[0037] Lipid modifications can be used to improve the pharmacokinetic profile of therapeutic peptides. Provided herein are compounds and methods useful in the preparation of peptides comprising one or more lipidated lysine resides. The compounds provided herein can be used in the preparation of lipidated peptides via peptide synthesis (e.g., solid phase peptide synthesis (SPPS) or liquid phase peptide synthesis (LPPS)). The compounds and methods provided herein can be used to produce lipidated peptides with improved efficiency and / or scalability.Compounds

[0038] In one aspect, provided herein are compounds of Formula (I):and salts or stereoisomers thereof, wherein:RNPis hydrogen or a nitrogen protecting group;ROPis hydrogen, C1-6 alkyl, an oxygen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS); andROP1and ROP2are each independently hydrogen, Ci-6 alkyl, or an oxygen protecting group.

[0039] In some embodiments, the compound is of Formula (I'):or a salt thereof.

[0040] As defined herein, ROPis hydrogen, C1-6 alkyl, an oxygen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS).

[0041] In some embodiments, Ropis hydrogen.Attorney Docket No. METS-031 / 01WO 350242-2279

[0042] In some embodiments, the compound of Formula (I) is of Formula (II):(II),or a salt or a stereoisomer thereof.

[0043] In some embodiments, the compound of Formula (I) is of Formula (IF):or a salt thereof.

[0044] In some embodiments, Ropis Ci-6 alkyl. In some embodiments, Ropis an oxygen protecting group. In some embodiments, Ropis LBu or benzyl (Bn or Bzl).

[0045] In some embodiments, ROPis a resin for solid phase peptide synthesis (SPPS). Resins useful in solid phase peptide synthesis are known. See, e.g., Shelton et. al. “Linkers, resins, and general procedures for solid-phase peptide synthesis.” Peptide Synthesis and Applications (2013): 23-41; Coin et al. “Solid-phase peptide synthesis: from standard procedures to the synthesis of difficult sequences.” Nat Protoc. 2, 3247-3256 (2007). Resins for SPPS often include a polymer and a linking group for attachment of the polymer to the C-terminus of an amino acid or peptide.

[0046] Non-limiting examples of resins for SPPS include polystyrene core resins, polyacrylate core resins, polyacrylamide core resins, and polyethylene glycol resins, Merrifield resins (chloromethylated polystyrene resins), hydroxymethyl resins (e.g., hydroxymethyl polystyrene resins), 2-chlorotrityl resins (e.g., 2-chlorotrityl chloride (2-CTC)), 4-(hydroxmethyl)phenoxyacetic acid (HMP) resins, Wang resins, hydrazide resins, diphenyldiazomethane (PDDM) resins, MAPS resins, TentaGel resins, amino core resins such as aminomethyl (AM) resins (e.g., aminomethyl polystyrene), 4-methylbenzhydryl amine (MBHA) resins, and amide resins such as Rink amide resins (e.g., Rink amide resin, RinkAttorney Docket No. METS-031 / 01WO 350242-2279amide AM resin, Rink amide BHA resin, Rink amide MBHA resin, Rink amide ProTide resin) and Ramage amide resins (e.g., Ramage amide resin, Ramage amide- AM resin, Ramage amide- MBHA resin, TentaGel Ramage resin).

[0047] In some embodiments, Ropis a 2-chlorotrityl chloride (2-CTC) resin. In someClembodiments, the 2-CTC resinis, wherein P is a polymer. In some embodiments, Ropis a diphenyldiazomethane (PDDM) resin. In some embodiments, the, wherein P is a polymer. In some embodiments, Ropis a Wangresin. In some embodiments, the Wang resinis wherein P is a polymer. In some embodiments, P comprises a styrene. In each instance, P is polystyrene. In some embodiments, Pis a polystyrene-based polymer. In some embodiments, Pis a copolymer comprising styrene. In some embodiments, P is poly(styrene-co-divinylbenzene).

[0048] In some embodiments, Ropis a tag for liquid phase peptide synthesis (LPPS). A “tag” in the context of LPPS refers to a molecule (e.g., small molecule) that allows for separation and purification of the peptide from a reaction mixture. In some instances, the tag allows for precipitation or extraction of the peptide. Examples of tags for LPPS are known. See, e.g., Sharma et al. “Liquid-Phase Peptide Synthesis (LPPS): A Third Wave for the Preparation of Peptides” Chemical Reviews 2022, 122(16), 13516-13546; Tamiaki etal. Bull. Chem. Soc. Jpn.2001, 74, 733-738; Tana et al. Chem. Commun. 2002, 237, 2-14; Kitada et al. Bioorg. Med. Chem. Lett. 2011, 21, 4476-4479; Fujita et al. Org. Lett. 2013, 15(6), 1155-1157; and Takahashi et. al. Angew. Chem. Int. Ed. 2017, 56, 7803-7807, all of which are herein incorporated by reference. Non-limited examples of tags for LPPS include benzyl tags as described.Attorney Docket No. METS-031 / 01WO 350242-2279

[0049] In some embodiments, Ropis a substituted benzyl tag. In some embodiments, the^r^OPhysubstituted benzyl tagisPhy, wherein Phy = phytyl.

[0050] As defined herein, ROP1is hydrogen, Ci-6 alkyl, or an oxygen protecting group. In some embodiments, ROP1is hydrogen. In some embodiments, ROP1is Ci-6 alkyl. In some embodiments, ROP1is Ci-4 alkyl. In some embodiments, ROP1is / -Bu.

[0051] In some embodiments, ROP1is an oxygen protecting group. In some embodiments, the oxygen protecting group is / -Bu, allyl, or benzyl. In some embodiments, ROP1is / -Bu. In some embodiments, ROP1is allyl (All). In some embodiments, ROP1is benzyl (Bn or Bzl)

[0052] As defined herein, ROP2is hydrogen, Ci-6 alkyl, or an oxygen protecting group. In some embodiments, ROP2is hydrogen. In some embodiments, ROP2is Ci-6 alkyl. In some embodiments, ROP2is Ci-4 alkyl. In some embodiments, ROP2is / -Bu.

[0053] In some embodiments, ROP2is an oxygen protecting group. In some embodiments, the oxygen protecting group is / -Bu, allyl, or benzyl. In some embodiments, ROP2is / -Bu. In some embodiments, ROP2is allyl (All). In some embodiments, ROP2is benzyl (Bn or Bzl).

[0054] In some embodiments, ROP1and ROP2are the same. In some embodiments, ROP1and ROP2are different.

[0055] In some embodiments, ROP1and ROP2are hydrogen. In some embodiments, ROP1and ROP2are each independently Ci-6 alkyl. In some embodiments, ROP1and ROP2are each independently Ci-4 alkyl. In some embodiments, ROP1and ROP2are / -Bu.

[0056] In some embodiments, ROP1and ROP2are an oxygen protecting group. In some embodiments, the oxygen protecting group is / -Bu, allyl, or benzyl. In some embodiments, ROP1and ROP2are / -Bu. In some embodiments, ROP1and ROP2are allyl (All). In some embodiments, ROP1and ROP2are benzyl (Bn or Bzl).

[0057] As defined herein, RNPis hydrogen or a nitrogen protecting group. In some embodiments, RNPis hydrogen. In some embodiments, RNPis a nitrogen protecting group. In some embodiments, the nitrogen protecting group is Bn, Boc, Cbz, Fmoc, trifluoroacetyl, triphenylmethyl, acetyl, or Ts. In some embodiments, RNPis Fmoc, Boc, or Cbz. In some embodiments, RNPis Fmoc.

[0058] In some embodiments, RNPis a nitrogen protecting group and together with the nitrogen atom to which the nitrogen protecting group is attached forms a carbamate group.

[0059] In some embodiments, the compound is of Formula (I-a):Attorney Docket No. METS-031 / 01WO 350242-2279(I-a), or a salt or a stereoisomer thereof.

[0060] For example, in some embodiments, the compound is Compound (A):or a salt thereof.

[0061] In some embodiments, the compound is of Formula (I-b):(I-b), or a salt or a stereoisomer thereof.

[0062] For example, in some embodiments, the compound is Compound (B):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt thereof.

[0063] In some embodiments, the compound is of any one of Formulae (I-c)-(I-f):(I-c),(I-d),Attorney Docket No. METS-031 / 01WO 350242-2279(I-e), or(I-f),or a salt or a stereoisomer thereof, wherein P is a polymer. In some embodiments, P comprises a styrene. In some embodiments, P is polystyrene. In some embodiments, P is a polystyrene-based polymer. In some embodiments, P is a copolymer comprising styrene. In some embodiments, P is poly(styrene-co-divinylbenzene).

[0064] In some embodiments, the compound is any one of Compounds (C)-(F):Attorney Docket No. METS-031 / 01WO 350242-2279(F),or a salt thereof, wherein P is a polymer. In some embodiments, P comprises a styrene. In some embodiments, P is polystyrene. In some embodiments, P is a polystyrene-based polymer. In some embodiments, P is a copolymer comprising styrene. In some embodiments, P is poly(styrene-co-divinylbenzene).

[0065] Also provided herein are compounds useful in preparing lipidated peptides comprising an amidated C-terminus. Provided herein are compounds of Formula (III):Attorney Docket No. METS-031 / 01WO 350242-2279and salts and stereoisomers thereof, wherein:RNPis hydrogen or a nitrogen protecting group;RNP1is hydrogen, a nitrogen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS); andROP1and ROP2are each independently hydrogen, Ci-6 alkyl, or an oxygen protecting group.

[0066] In some embodiments, the compound is of Formula (IIP):or a salt thereof.

[0067] As defined herein, RNP1is hydrogen, a nitrogen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS).

[0068] In some embodiments, RNP1is hydrogen.

[0069] In some embodiments, the compound of Formula (III) is of Formula (IV):or a salt or a stereoisomer thereof.

[0070] In some embodiments, the compound of Formula (III) is of Formula (IV'):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt thereof.

[0071] In some embodiments, RNP1is a nitrogen protecting group. Examples of nitrogen protecting groups are provided herein.

[0072] In some embodiments, RNP1is a resin for solid phase peptide synthesis (SPPS). Examples of resins for SPPS are provided herein. In some embodiments, the peptide resulting from SPPS can be cleaved from the resin to yield a peptide comprising an amidated C-terminus.

[0073] In some embodiments, RNP1is a resin for SPPS and the resin is a Rink amide resin, a PAL resin, or a Ramage amide resin. In some embodiments, RNP1is a Rink amide resin. In some embodiments, the Rink amide resin is a Rink amide AM resin, a Rink amide BHA resin, a Rink amide MBHA resin, or a Rink amide ProTide resin. In some embodiments, RNP1is a PAL resin (4-alkoxy-2,6-dimethoxybenzylamine resin). In some embodiments, RNP1is a Ramage amide resin. In some embodiments, the Ramage amide resin is a Ramage amide- AM resin, a Ramage amide-MBHA resin, or a TentaGel Ramage resin.

[0074] In some embodiments, RNP1is a is a tag for liquid phase peptide synthesis (LPPS). Examples of tags for LPPS are provided herein.

[0075] As defined herein, ROP1is hydrogen, Ci-6 alkyl, or an oxygen protecting group. In some embodiments, ROP1is hydrogen. In some embodiments, ROP1is Ci-6 alkyl. In some embodiments, ROP1is Ci-4 alkyl. In some embodiments, ROP1is t-Bu.

[0076] In some embodiments, ROP1is an oxygen protecting group. In some embodiments, the oxygen protecting group is t-Bu, allyl, or benzyl. In some embodiments, ROP1is t-Bu. In some embodiments, ROP1is allyl (All). In some embodiments, ROP1is benzyl (Bn or Bzl)

[0077] As defined herein, ROP2is hydrogen, Ci-6 alkyl, or an oxygen protecting group. In some embodiments, ROP2is hydrogen. In some embodiments, ROP2is Ci-6 alkyl. In some embodiments, ROP2is Ci-4 alkyl. In some embodiments, ROP2is t-Bu.

[0078] In some embodiments, ROP2is an oxygen protecting group. In some embodiments, the oxygen protecting group is t-Bu, allyl, or benzyl. In some embodiments, ROP2is t-Bu. In some embodiments, ROP2is allyl (All). In some embodiments, ROP2is benzyl (Bn or Bzl).Attorney Docket No. METS-031 / 01WO 350242-2279

[0079] In some embodiments, ROP1and ROP2are the same. In some embodiments, ROP1and ROP2are different.

[0080] In some embodiments, ROP1and ROP2are hydrogen. In some embodiments, ROP1and ROP2are each independently Ci-6 alkyl. In some embodiments, ROP1and ROP2are each independently Ci-4 alkyl. In some embodiments, ROP1and ROP2are / -Bu. In

[0081] In some embodiments, ROP1and ROP2are each independently an oxygen protecting group. In some embodiments, the oxygen protecting group is t-Bu, allyl, or benzyl. In some embodiments, ROP1and ROP2are t-Bu. In some embodiments, ROP1and ROP2are allyl (All). In some embodiments, ROP1and ROP2are benzyl (Bn or Bzl).

[0082] As defined herein, RNPis hydrogen or a nitrogen protecting group. In some embodiments, RNPis hydrogen. In some embodiments, RNPis a nitrogen protecting group. In some embodiments, the nitrogen protecting group is Bn, Boc, Cbz, Fmoc, trifluoroacetyl, triphenylmethyl, acetyl, or Ts. In some embodiments, RNPis Fmoc, Boc, or Cbz. In some embodiments, RNPis Fmoc.

[0083] In some embodiments, RNPis a nitrogen protecting group and together with the nitrogen atom to which the nitrogen protecting group is attached forms a carbamate nitrogen protecting group.Methods for Preparing Lipidated Peptides

[0084] Compounds provided herein can be used to prepare lipidated peptides via peptide synthesis (e.g., solid phase peptide synthesis (SPPS) or liquid phase peptide synthesis (LPPS)). Methods of SPPS and LPPS are known in the art. See, c.g, Shelton et. al. “Linkers, resins, and general procedures for solid-phase peptide synthesis.” Peptide Synthesis and Applications (2013): 23-41; Coin et al. “Solid-phase peptide synthesis: from standard procedures to the synthesis of difficult sequences.” Nat Protoc. 2, 3247-3256 (2007); and Sharma et al. “Liquid-Phase Peptide Synthesis (LPPS): A Third Wave for the Preparation of Peptides” Chemical Reviews 2022, 122(16), 13516-13546, all of which are herein incorporated by reference. Compounds provided herein can be used in SPPS and / or LPPS methods to access peptides of interest with improved efficiency and / or scalability.

[0085] Methods provided herein may start with a step of attaching a compound of Formula (II) (i.e., a compound of Formula (I) wherein Ropis hydrogen) to a resin for SPPS or a tag for LPPS. For example, provided herein are methods for solid or liquid phase synthesis of a peptide, the methods comprising:(i) reacting a compound of Formula (II):Attorney Docket No. METS-031 / 01WO 350242-2279(II),or a salt or a stereoisomer thereof, with a reagent for a resin for SPPS or a reagent for a tag for LPPS, to form a compound of Formula (S-l):(S-l), or a salt or a stereoisomer thereof, wherein:RNPis a nitrogen protecting group;ROP1and ROP2are each independently C1-6alkyl or an oxygen protecting group; and S is a resin for SPPS or a tag for LPPS;(ii) deprotecting the compound of Formula (S-l), or a salt or a stereoisomer thereof, under conditions sufficient to remove the RNPprotecting group, to yield a compound of Formula (S-2):(S-2), or a salt or a stereoisomer thereof;(iii) reacting the compound of Formula (S-2), or a salt or a stereoisomer thereof, with an N-terminal protected amino acid or peptide to yield a compound of Formula (S-3):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt or a stereoisomer thereof, wherein A is an amino acid or peptide, and RAPis an N-terminal protecting group;(iv) optionally, (a) removing the N-terminal protecting group RAPunder conditions sufficient to remove the N-terminal protecting group and (b) reacting the resulting compound, or a salt or a stereoisomer thereof, with an additional N-terminal protected amino acid or peptide, and (c) optionally repeating steps (a) and (b) until a peptide with a desired amino acid sequence is obtained; and(v) optionally, deprotecting the resulting compound or a salt or a stereoisomer thereof in one or more steps under conditions sufficient to remove RAP, N-terminal protecting group, ROP1, and / or ROP2protecting groups; and(vi) optionally, cleaving S (the resin or the tag) from the resulting compound or a salt or a stereoisomer thereof to provide a lipidated peptide.

[0086] In some embodiments, the compound of Formula (II) is a compound of Formula (IF) described herein.

[0087] In some embodiments, the reagent for a resin for SPPS or the reagent for a tag for LPPS is any one of the resin for SPPS or the tag for LPPS as described herein having a group that can be reacted with a carboxylic acid group. In some embodiments, the group that can be reacted with a carboxylic acid group is a halogen, hydroxyl, or diazo group. In some embodiments, the reagent for a resin for SPPS is 2-chlorotrityl chloride resin, 4-alkoxybenzyl alcohol resin (a reagent for Wang resin), or diphenyldiazomethane resin (a reagent for DPPM resin).

[0088] In some embodiments, the reagent for a tag for LPPS is a substituted benzyl alcohol. In OPhysome embodiments, the reagent for a tagfor LPPS isPhy

[0089] In some embodiments, the resin for SPPS or the tag for LPPS is any one of the resin for SPPS or the tag for LPPS described herein.Attorney Docket No. METS-031 / 01WO 350242-2279

[0090] In some embodiments, an N-terminal protecting group for an amino acid or peptide is any one of the nitrogen protecting group described herein. In some embodiments, an N-terminal protecting group for an amino acid or peptide is Fmoc or Boc.

[0091] Alternatively, a compound of Formula (I) may be provided pre-functionalized with a resin for SPPS or a tag for LPPS (i.e., Formula (I) wherein Ropis a resin for SPPS or a tag for LPPS). For example, provided herein are methods for solid or liquid phase synthesis of a peptide, the methods comprising:(i) reacting a compound of Formula (I):(I),or a salt thereof, under conditions sufficient to remove the RNPprotecting group, to form a compound of Formula (S-i):(S-i), or a salt or a stereoisomer thereof, wherein:RNPis a nitrogen protecting group;ROP1and ROP2are each independently C1-6alkyl or an oxygen protecting group; and ROPa resin for SPPS or a tag for LPPS;(ii) reacting the compound of Formula (S-i), or a salt or a stereoisomer thereof, with an N-terminal protected amino acid or peptide to for a compound of Formula (S-ii):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt or a stereoisomer thereof, wherein A is an amino acid or a peptide and RAPis an N-terminal protecting group;(iii) optionally, (a) removing the N-terminal protecting group RAPunder conditions sufficient to remove the N-terminal protecting group and (b) reacting the resulting compound, or a salt or a stereoisomer thereof, with an additional N-terminal protected amino acid or peptide, and (c) optionally repeating steps (a) and (b) until a peptide with a desired amino acid sequence is obtained; and(v) optionally, deprotecting the resulting compound or a salt or a stereoisomer thereof in one or more steps under conditions sufficient to remove RAP, N-terminal protecting group, ROP1, and / or ROP2protecting groups; and(vi) optionally, cleaving ROP(the resin or the tag) from the resulting compound or a salt or a stereoisomer thereof to provide a lipidated peptide.

[0092] In some embodiments, the compound of Formula (I) is a compound of Formula (I') described herein.

[0093] In some embodiments, the resin for SPPS or the tag for LPPS is any one of the resin for SPPS or the tag for LPPS described herein.

[0094] In some embodiments, an N-terminal protecting group for an amino acid or peptide is any one of the nitrogen protecting group described herein. In some embodiments, an N-terminal protecting group for an amino acid or peptide is Fmoc or Boc.

[0095] In some embodiments, the methods for solid or liquid phase synthesis of a peptide further comprises the step of further forming one or more peptide bonds at the C-terminal. In some embodiments, the method provides a compound of Formula (S-iii)Attorney Docket No. METS-031 / 01WO 350242-2279(S-iii),or a salt or a stereoisomer thereof, wherein AA and BB are each independently an amino acid or a peptide, wherein the compound is optionally acylated at the N-terminus of AA and the compound is optionally amidated at the C-terminus of BB.

[0096] Analogous methods can be used to prepare lipidated peptides comprising amidated C-termini (e.g., starting from compounds of Formulae (III) and (IV)).

[0097] In some embodiments, provided herein are methods for solid or liquid phase synthesis of a peptide, the methods comprising:(i) reacting a compound of Formula (IV):(IV),or a salt or a stereoisomer thereof, with a reagent for a resin for SPPS or a reagent for a tag for LPPS, to form a compound of Formula (S-4):or a salt or a stereoisomer thereof, wherein:RNP1is hydrogen;RNPis a nitrogen protecting group;ROP1and ROP2are each independently C1-6alkyl or an oxygen protecting group; and S is a resin for SPPS or a tag for LPPS;Attorney Docket No. METS-031 / 01WO 350242-2279(ii) deprotecting the compound of Formula (S-4), or a salt or a stereoisomer thereof, under conditions sufficient to remove the RNPprotecting group, to yield a compound of Formula (S-5):N— ( SH ROP1 ROP2 A Oo r iNHor a salt or a stereoisomer thereof;(iii) reacting the compound of Formula (S-5), or a salt or a stereoisomer thereof, with an N-terminal protected amino acid or peptide to yield a compound of Formula (S-6):- — H RAP— A— NN— ( SH NA ROP1 ROP2 A OO TiNHor a salt or a stereoisomer thereof, wherein A is an amino acid or peptide, and RAPis an N-terminal protecting group;(iv) optionally, (a) removing the N-terminal protecting group RAPunder conditions sufficient to remove the N-terminal protecting group and (b) reacting the resulting compound, or a salt or a stereoisomer thereof, with an additional N-terminal protected amino acid or peptide, and (c) optionally repeating steps (a) and (b) until a peptide with a desired amino acid sequence is obtained; and(v) optionally, deprotecting the resulting peptide in one or more steps under conditions sufficient to remove RAP, N-terminal protecting group, ROP1, and / or ROP2protecting groups; and(vi) optionally, cleaving S (the resin or the tag) from the resulting compound or a salt or a stereoisomer thereof to provide a lipidated peptide.

[0098] In some embodiments, the compound of Formula (IV) is a compound of Formula (IV') described herein.Attorney Docket No. METS-031 / 01WO 350242-2279

[0099] In some embodiments, the reagent for a resin for SPPS or the reagent for a tag for LPPS is any one of the resin for SPPS or the tag for LPPS as described herein having a group that can be reacted with an amide group. In some embodiments, the group that can be reacted with an amide group is a halogen, hydroxyl, or diazo group. In some embodiments, the reagent for a resin for SPPS is 2-chlorotrityl chloride resin, 4-alkoxybenzyl alcohol resin (a reagent for Wang resin), or diphenyldiazomethane resin (a reagent for DPPM resin).

[0100] In some embodiments, the reagent for a tag for LPPS is a substituted benzyl alcohol. Insome embodiments, the reagent for a tagfor LPPS is

[0101] In some embodiments, the resin for SPPS or the tag for LPPS is any one of the resin for SPPS or the tag for LPPS described herein.

[0102] In some embodiments, an N-terminal protecting group for an amino acid or peptide is any one of the nitrogen protecting group described herein. In some embodiments, an N-terminal protecting group for an amino acid or peptide is Fmoc or Boc.

[0103] In some embodiments, a compound of Formula (IV) may be provided prefunctionalized with a resin for SPPS or a tag for LPPS (i.e., Formula (III) wherein RNP1is a resin for SPPS or a tag for LPPS). For example, provided herein are methods for solid or liquid phase synthesis of a peptide, the methods comprising:(i) reacting a compound of Formula (III):or a salt thereof, under conditions sufficient to remove the RNPprotecting group, to form a compound of Formula (S-iv):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt or a stereoisomer thereof, wherein:RNPis a nitrogen protecting group;ROP1and ROP2are each independently C1-6alkyl or an oxygen protecting group; and RNP1a resin for SPPS or a tag for LPPS;(ii) reacting the compound of Formula (S-iv), or a salt or a stereoisomer thereof, with an N-terminal protected amino acid or peptide to for a compound of Formula (S-v):terminal protecting group;(iii) optionally, (a) removing the N-terminal protecting group RAPunder conditions sufficient to remove the N-terminal protecting group and (b) reacting the resulting compound, or a salt or a stereoisomer thereof, with an additional N-terminal protected amino acid or peptide, and (c) optionally repeating steps (a) and (b) until a peptide with a desired amino acid sequence is obtained; and(v) optionally, deprotecting the resulting peptide in one or more steps under conditions sufficient to remove RPA, N-terminal protecting group, ROP1, and / or ROP2protecting groups; and(vi) optionally, cleaving RNP1(the resin or the tag) from the resulting compound or a salt or a stereoisomer thereof to provide a lipidated peptide.

[0104] In some embodiments, the compound of Formula (III) is a compound of Formula (IIP) described herein.Attorney Docket No. METS-031 / 01WO 350242-2279

[0105] In some embodiments, the resin for SPPS or the tag for LPPS is any one of the resin for SPPS or the tag for LPPS described herein.

[0106] In some embodiments, an N-terminal protecting group for an amino acid or peptide is any one of the nitrogen protecting group described herein. In some embodiments, an N-terminal protecting group for an amino acid or peptide is Fmoc or Boc.EXAMPLES

[0107] Example 1. Synthesis of Compound 1Compound 1

[0108] Compound 1 acetate comprises a peptide of 41 amino acids covalently conjugated via the Lys41 residue side chain to a gamma-Glu-eicosanedioic acid linker.

[0109] Compound 1 acetate was made via a stepwise solid phase peptide synthesis (SPPS) followed by cleavage and deprotection, purification, salt exchange and isolation by lyophilization. This synthesis used a 9-fluorenylmethyloxycarbonyl (Fmoc) / tert-butyl (tBu) protecting group strategy starting from 2-chlorotrityl chloride resin.

[0110] The synthesis and cleavage and deprotection steps used in this process are provided below.

[0111] Step 1: Solid Phase Peptide Synthesis (SPPS)O' oN"Ac" Nr’V’COOH / :Fmoc-Lys(ivDde)-OHAttorney Docket No. METS-031 / 01WO 350242-2279

[0112] The 2-chlorotrityl chloride resin was swollen in dichloromethane (DCM, about 10 mg / mL). The resin was then activated by addition of acetyl chloride (AcCl, 20% v / v) in DCM and washed with DCM. The resin was loaded with 1.0eq Fmoc-Lys(ivDde)-OH in DMF, in the presence of diisopropylethylamine (DIPEA, 2.0eq) as an activating reagent. The loaded resin was capped with a solution of methanol and DIPEA in DMF, followed by washes with DMF and isopropyl alcohol (IP A).

[0113] Suitably protected amino-acid derivatives or dipeptides were used as building blocks (i.e., starting materials). Protection of the reactive a-amino groups used Fmoc strategy. Necessary side-chain protection was achieved using other protecting groups that are stable toward the reagents used for Fmoc-cleavage.

[0114] During SPPS, the peptide chain was built up on a cross-linked polystyrene resin support by sequential and repetitive addition of the chosen building blocks from the C-terminus to the N-terminus, according to the following conditions.• N-a deprotection with piperidine (20%v / v) in DMF to enable the coupling reaction for all cycles except for cycles 19 where piperidine in N-methylpyrrolidone (NMP) was used, and cycle 39 where ivDde was removed using 5% v / v hydrazine in DMF. Fmoc deprotection with piperidine was not performed in cycle 39.• Coupling of protected building blocks (2 eq. of protected amino acid derivative or dipeptide derivatives):• Coupling in the presence of diisopropylcarbodiimide (DIC, 4 eq.) and Oxyma (3 eq.) in DMF for cycles 3 to 19, 21, and 23 to 39.• Coupling in the presence of TCTU (1.9 eq.) and DIPEA (2eq) in DMF for cycles 2, 20, and 22.• Coupling in the presence of DIC (4eq) and Oxyma (3 eq.) in NMP for cycle 40 • Colorimetric in-process control (IPC) testing was performed to confirm coupling.• Acetylation (capping) of remaining free amino groups using a mixture of acetic anhydride and pyridine in DMF was performed in cycles 4, and 19-24.

[0115] After the last coupling step, the peptide resin was washed alternatingly with DMF and IPA. After a final washing with IP A, the resin was dried under reduced pressure to yield about 20 kg of dried peptidyl resin.

[0116] Step 2: Trifluoroacetic acid (TFA) Cleavage and Deprotection.Attorney Docket No. METS-031 / 01WO 350242-2279

[0117] Cleavage of the peptide from the resin and simultaneous cleavage of the side-chain protecting groups was accomplished by treating the peptide resin with TFA in the presence of TFA: H2O: triisopropylsilane [TIS]: 1,2-ethanedithiol [EDT], 92.5: 2.5: 2.5: 2.5. After filtering and washing the resin with TFA, the product was precipitated in cooled isopropyl ether (IPE) (60mL / g of peptidyl resin). The solid obtained was filtered, washed with IPE, and dried under reduced pressure to yield about 7.4 kg of crude peptide.

[0118] Analogous methods can be used to prepare various lipidated peptides, for example lipidated peptides comprising amidated C-termini (e.g., starting from compounds of Formulae (III) and (IV)). These methods may also be adapted to make lipidated peptides wherein the lipid is attached to an amino acid located at an internal position of the sequence ( / .<., not at C-terminus), for example by making a lipidated peptide intermediate and subsequently using N-to-C peptide synthesis to make the remainder of the desired peptide

[0119] In the claims articles such as “a,” “an,” and “the” may mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include “or” between one or more members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The present disclosure includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The present disclosure includes embodiments in which more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process.

[0120] Furthermore, the present disclosure encompasses all variations, combinations, and permutations in which one or more limitations, elements, clauses, and descriptive terms from one or more of the listed claims is introduced into another claim. For example, any claim that is dependent on another claim can be modified to include one or more limitations found in any other claim that is dependent on the same base claim. Where elements are presented as lists, e.g., in Markush group format, each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should be understood that, in general, where the present disclosure, or aspects of the present disclosure, is / are referred to as comprising particular elements and / or features, certain embodiments of the present disclosure or aspects of the present disclosure consist, or consist essentially of, such elements and / or features. For purposes of simplicity, those embodiments have not been specifically set forth in haec verbaAttorney Docket No. METS-031 / 01WO 350242-2279herein. It is also noted that the terms “comprising” and “containing” are intended to be open and permits the inclusion of additional elements or steps. Where ranges are given, endpoints are included. Furthermore, unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or sub-range within the stated ranges in different embodiments of the present disclosure, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise.

[0121] This application refers to various issued patents, published patent applications, journal articles, and other publications, all of which are incorporated herein by reference. If there is a conflict between any of the incorporated references and the instant specification, the specification shall control. In addition, any particular embodiment of the present disclosure that falls within the prior art may be explicitly excluded from any one or more of the claims. Because such embodiments are deemed to be known to one of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein. Any particular embodiment of the present disclosure can be excluded from any claim, for any reason, whether or not related to the existence of prior art.

[0122] Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation many equivalents to the specific embodiments described herein. The scope of the present embodiments described herein is not intended to be limited to the above Description, but rather is as set forth in the appended claims. Those of ordinary skill in the art will appreciate that various changes and modifications to this description may be made without departing from the spirit or scope of the present disclosure, as defined in the following claims.

Claims

Attorney Docket No. METS-031 / 01WO 350242-2279CLAIMSWhat is claimed is:

1. A compound of Formula (I):or a salt or a stereoisomer thereof, wherein:RNPis hydrogen or a nitrogen protecting group;ROPis hydrogen, C1-6 alkyl, an oxygen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS); andROP1and ROP2are each independently hydrogen, C1-6alkyl, or an oxygen protecting group.

2. The compound of claim 1, wherein the compound has the structure of Formula (I'):

3. The compound of claim 1 or 2, or a salt or a stereoisomer thereof, wherein Ropis hydrogen.

4. The compound of claim 1 or 2, or a salt or a stereoisomer thereof, wherein Ropis an oxygen protecting group.Attorney Docket No. METS-031 / 01WO 350242-22795. The compound of claim 1 or 2, or a salt or a stereoisomer thereof, wherein Ropis C1-6alkyl.

6. The compound of any one of claims 1, 2, and 4, or a salt or a stereoisomer thereof, wherein Ropis an oxygen protecting group and the oxygen protecting group is / -butyl or benzyl.

7. The compound of claim 1 or 2, or a salt or a stereoisomer thereof, wherein Ropis a resin for SPPS.

8. The compound of any one of claims 1, 2, and 7 or a salt or a stereoisomer thereof, wherein Ropis a resin for SPPS and the resin is a 2-CTC resin, a PDDM resin, or a Wang resin.

9. The compound of claim 1 or 2, or a salt or a stereoisomer thereof, wherein Ropis a tag for LPPS.

10. The compound of any one of claims 1, 2, and 9, or a salt or a stereoisomer thereof, wherein Ropis a tag for LPPS and the tag is a benzyl tag.

11. The compound of claim 1 or 2, or a salt or a stereoisomer thereof, wherein Ropis a tag OPhyOPhyfor LPPS and the tag is12. A compound of Formula (III):or a salt or a stereoisomer thereof, wherein:RNPis hydrogen or a nitrogen protecting group;Attorney Docket No. METS-031 / 01WO 350242-2279RNP1is hydrogen, a nitrogen protecting group, a resin for solid phase peptide synthesis (SPPS), or a tag for liquid phase peptide synthesis (LPPS); andROP1and ROP2are each independently hydrogen, C1-6alkyl, or an oxygen protecting group.

13. The compound of claim 12, wherein the compound has the structure of Formula (IIP):

14. The compound of claim 12 or 13, or a salt or a stereoisomer thereof, wherein RNP1is hydrogen.

15. The compound of claim 12 or 13, or a salt or a stereoisomer thereof, wherein RNP1is a resin for SPPS.

16. The compound of any one of claims 12, 13, and 15, or a salt or a stereoisomer thereof, wherein RNP1is a resin for SPPS and the resin is a Rink amide resin, a PAL resin, or a Ramage amide resin.

17. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein RNPis a nitrogen protecting group.

18. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein RNPis a nitrogen protecting group and the nitrogen protecting group is Fmoc, Boc, or Cbz.

19. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein RNPis a nitrogen protecting group and the nitrogen protecting group is Fmoc.Attorney Docket No. METS-031 / 01WO 350242-227920. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein ROP1is an oxygen protecting group.

21. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein ROP1is an oxygen protecting group and the oxygen protecting group is allyl or benzyl.

22. The compound of any one of claims 1-19, or a salt or a stereoisomer thereof, wherein ROP1is C1-6alkyl.

23. The compound of any one of claims 1-19 and 22, or a salt or a stereoisomer thereof, wherein ROP1is / -Bu.

24. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein ROP2is an oxygen protecting group.

25. The compound of any one of the preceding claims, or a salt or a stereoisomer thereof, wherein ROP2is an oxygen protecting group and the oxygen protecting group is allyl or benzyl.

26. The compound of any one of claims 1-23, or a salt or a stereoisomer thereof, wherein ROP2is C1-6alkyl.

27. The compound of any one of claims 1-23 and 26, or a salt or a stereoisomer thereof, wherein ROP2is / -Bu.Attorney Docket No. METS-031 / 01WO 350242-227928. The compound of claim 1, wherein the compound has the structure of Formula (I-a) or (I-b):(I-a), oror a salt or a stereoisomer thereof.Attorney Docket No. METS-031 / 01WO 350242-2279 29. The compound of claim 1, wherein the compound is Compound (A) or (B):(A), oror a salt thereof.Attorney Docket No. METS-031 / 01WO 350242-227930. The compound of claim 1, wherein the compound has the structure of Formula (I-c), (I-d), (I-e), or (I-f):(I-e), orAttorney Docket No. METS-031 / 01WO 350242-2279(I-f),or a salt or a stereoisomer thereof, wherein P is a polymer.

31. The compound of claim 1, wherein the compound is Compound (C), (D), (E), or (F):(C),(D),Attorney Docket No. METS-031 / 01WO 350242-2279(E), or(F),or a salt thereof, wherein P is a polymer.

32. A method for solid or liquid phase synthesis of a peptide, the method comprising:(i) reacting a compound of Formula (II):or a salt or a stereoisomer thereof, with a reagent for a resin for SPPS or a reagent for a tag for LPPS, to form a compound of Formula (S-l):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt or a stereoisomer thereof, wherein:RNPis a nitrogen protecting group;ROP1and ROP2are each independently C1-6alkyl or an oxygen protecting group; and S is a resin for SPPS or a tag for LPPS;(ii) deprotecting the compound of Formula (S-l), or a salt or a stereoisomer thereof, under conditions sufficient to remove the RNPprotecting group, to yield a compound of Formula (S-2):or a salt or a stereoisomer thereof;(iii) reacting the compound of Formula (S-2), or a salt or a stereoisomer thereof, with an N-terminal protected amino acid or peptide to for a compound of Formula (S-3):terminal protecting group;(iv) optionally, (a) removing the N-terminal protecting group RAPunder conditions sufficient to remove the N-terminal protecting group and (b) reacting the resulting compound, or a salt or a stereoisomer thereof, with an additional N-terminal protected amino acid orAttorney Docket No. METS-031 / 01WO 350242-2279peptide, and (c) optionally repeating steps (a) and (b) until a peptide with a desired amino acid sequence is obtained; and(v) optionally, deprotecting the resulting compound or a salt or a stereoisomer thereof in one or more steps under conditions sufficient to remove RAP, N-terminal protecting group, ROP1, and / or ROP2protecting groups; and(vi) optionally, cleaving S (the resin or the tag) from the resulting compound or a salt or a stereoisomer thereof to provide a lipidated peptide.

33. A method for solid or liquid phase synthesis of a peptide, the method comprising:(i) reacting a compound of Formula (I):(I),or a salt or a stereoisomer thereof, under conditions sufficient to remove the RNPprotecting group, to form a compound of Formula (S-i):(S-i), or a salt or a stereoisomer thereof, wherein:RNPis a nitrogen protecting group;ROP1and ROP2are each independently C1-6alkyl or an oxygen protecting group; and ROPa resin for SPPS or a tag for LPPS;(ii) reacting the compound of Formula (S-i), or a salt or a stereoisomer thereof, with an N-terminal protected amino acid or peptide to for a compound of Formula (S-ii):Attorney Docket No. METS-031 / 01WO 350242-2279or a salt or a stereoisomer thereof, wherein A is an amino acid or a peptide and RPAis an N-terminal protecting group;(iii) optionally, (a) removing the N-terminal protecting group RAPunder conditions sufficient to remove the N-terminal protecting group and (b) reacting the resulting compound, or a salt or a stereoisomer thereof, with an additional N-terminal protected amino acid or peptide, and (c) optionally repeating steps (a) and (b) until a peptide with a desired amino acid sequence is obtained; and(v) optionally, deprotecting the resulting compound or a salt or a stereoisomer thereof in one or more steps under conditions sufficient to remove the RPA, N-terminal protecting group, ROP1, and / or ROP2protecting groups; and(vi) optionally, cleaving ROP(the resin or the tag) from the resulting compound or a salt or a stereoisomer thereof to provide a lipidated peptide.

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