A method for synthesizing seven-membered ring ether compounds

Abstract

The present invention discloses a method for synthesizing a seven-membered cyclic ether compound, comprising the following steps: (1) reacting 2,4,6-trimethylpyridine nitrogen oxide with an alkyl p-toluenesulfonate in the presence of a solvent to obtain pyridine nitrogen oxide p-toluenesulfonate; and (2) subjecting pyridine nitrogen oxide p-toluenesulfonate to a cycloaddition reaction with a conjugated diene compound in the presence of a photocatalyst and a solvent under visible light irradiation to obtain the seven-membered cyclic ether compound. The above-mentioned synthesis method is simple to operate, has mild reaction conditions, requires a small amount of catalyst for the reaction, is time-consuming, and the product is easy to purify, making it suitable for industrial mass production. In addition, the reaction substrate of the synthesis method has wide applicability, and a seven-membered cyclic ether compound with multiple substituents can be designed and synthesized according to demand.

Description

Technical Field

[0001] The present invention relates to the technical field of oxygen-containing heterocyclic compounds, and in particular to a method for synthesizing seven-membered cyclic ether compounds. Background Art

[0002] Seven-membered cyclic ether compounds are widely used in biomedicine as drug intermediates or active ingredients. For example, naturally occurring drugs in nature contain many seven-membered cyclic ether compounds, including the natural product Cucurbitacin S with anti-cancer and anti-inflammatory effects, artemether used to treat malaria, the antifungal Aegicerin, and the antitumor drug Miliusane XIX.

[0003]

[0004] However, the current synthesis methods for preparing seven-membered cyclic ether compounds generally have problems such as harsh reaction conditions and large substrate limitations. For example, 1,6-dihexanol is used to undergo dehydration reaction at high temperature (~190°C, Journal of the American Chemical Society, (1999), 10711-10718, 121 (46)) or high pressure (200 standard atmospheres, Russian Journal of Organic Chemistry, (2017), 1840-1843, 53 (12)) to prepare seven-membered cyclic ethers. Since the reaction needs to be carried out at high temperature or high pressure, this type of synthesis method of seven-membered cyclic ethers is not only energy-intensive but also has significant safety hazards, making it unsuitable for industrial production. In addition, the above-mentioned synthesis method is limited in the types of substrates and is not suitable for the design and synthesis of new seven-membered cyclic ether compounds with multiple substituents or functional groups. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for synthesizing seven-membered cyclic ether compounds, in which a novel pyridine nitrogen oxide p-toluenesulfonate and a conjugated diene compound are subjected to a photocatalytic cyclization reaction to prepare the seven-membered cyclic ether compounds. The method has a simple operation method, mild reaction conditions, and a wide range of substrate applicability. The seven-membered cyclic ether compounds with multiple substituents can be designed and synthesized according to demand.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention provides a method for synthesizing a seven-membered ring ether compound, comprising the following steps:

[0008] (1) reacting 2,4,6-trimethylpyridine N-oxide with an alkyl p-toluenesulfonate represented by formula (I) in the presence of a first solvent to obtain a pyridine N-oxide p-toluenesulfonate represented by formula (II);

[0009] (2) Under visible light irradiation, the pyridine nitrogen oxide p-toluenesulfonate prepared in step (1) is subjected to a cycloaddition reaction with the conjugated diene compound represented by formula (III) in the presence of a photocatalyst and a second solvent to obtain a seven-membered cyclic ether compound represented by formula (IV);

[0010] The structures of the compounds represented by the above formula (I) to formula (IV) are shown below:

[0011]

[0012]

[0013] Wherein, R1 is selected from -CH=CH-, -C≡C-, -(CH2)2-CH=CH-, One of the following;

[0014] R2 and R3 are each selected from one of hydrogen and methyl;

[0015] R4, R5, and R6 are each selected from hydrogen, alkyl, and aryl, or R4 and R5 are cyclized to form a cyclopentyl or cyclohexyl group, or R5 and R6 are cyclized to form a cyclopentyl or adamantyl group;

[0016] Ar is a substituted or unsubstituted aryl or heteroaryl group.

[0017] Further, Ar is preferably phenyl, 2-thienyl, 4-trifluoromethylbenzene, 4-bromophenyl, 3,4-methylenedioxyphenyl, 2-methoxyphenyl, phenethyl, 4-phenylphenyl, 2-benzothienyl, 4-methoxyphenyl, 4-tolyl, 3-fluorophenyl, 4-tert-butylbenzene or 2-naphthyl.

[0018] Furthermore, in step (1), the molar ratio of 2,4,6-trimethylpyridine nitrogen oxide to alkyl p-toluenesulfonate is 1:1-1.2, such as 1:1, 1:1.1, 1:1.15, etc., including but not limited to the above molar ratios.

[0019] Furthermore, in step (1), the first solvent is selected from one or more of acetonitrile, N,N-dimethylformamide, methanol, tetrahydrofuran, dichloromethane and dichloroethane, such as acetonitrile.

[0020] Furthermore, in step (1), the reaction temperature is 70-80°C, such as 70°C, 75°C, 80°C, etc., and the reaction time is 8h-12h, such as 9h, 10h, 12h, etc.

[0021] Furthermore, in step (2), the visible light is preferably blue light and / or green light.

[0022] Furthermore, in step (2), the photocatalyst is fac-[Ir(ppy)3], 4CzIPN, [Ir(dF(Me)ppy)2(bpy)]PF6, [Ir(dF(CF3)ppy)2(bpy)]PF6, dinaphthylene or 10-phenyl-10H-phenothiazine; the molar ratio of the photocatalyst to the conjugated diene compound is 0.01-0.03:1, for example, 0.01:1, 0.02:1, 0.03:1, etc., including but not limited to the above molar ratios.

[0023] Furthermore, in step (2), the molar ratio of the pyridine nitrogen oxide p-toluenesulfonate to the conjugated diene compound is 0.5-3:1, for example, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc., including but not limited to the above molar ratios.

[0024] Furthermore, in step (2), the reaction temperature of the cycloaddition reaction is 0-50°C, more preferably 20-30°C, for example 25°C; the reaction time is 15 min-12 h, more preferably 2-5 h, for example 2.5 h, 3 h, 3.5 h, 4 h, etc.

[0025] Furthermore, in step (2), the second solvent is selected from one or more of acetonitrile, N,N-dimethylformamide, methanol, tetrahydrofuran, dichloromethane and dichloroethane, such as dichloromethane.

[0026] Furthermore, the seven-membered ring ether compound is one of the compounds shown in the following structure:

[0027]

[0028]

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a method for synthesizing seven-membered cyclic ether compounds. The seven-membered cyclic ether compounds are prepared by photocatalytic cyclization of pyridine nitrogen oxide p-toluenesulfonate with a conjugated diene compound under the action of visible light. This synthesis method is simple to operate, has mild reaction conditions, and does not require high temperature, high pressure, or other reaction conditions, resulting in high safety. Furthermore, the reaction requires a small amount of catalyst, is time-efficient, and the product is easy to purify, making it suitable for industrial mass production. Furthermore, the reaction substrates of this synthesis method are widely applicable, and seven-membered cyclic ether compounds with different multi-substitution groups can be synthesized according to demand. This method has promising application prospects in the synthesis of new drugs and small organic molecules. DETAILED DESCRIPTION

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] The present invention will be further described below with reference to specific examples so that those skilled in the art can better understand the present invention and implement it, but the examples are not intended to limit the present invention.

[0033] Example 1

[0034] This embodiment relates to the preparation of a novel pyridine nitrogen oxide p-toluenesulfonate, and the synthesis method is as follows:

[0035]

[0036] The specific method is as follows:

[0037] 2,4,6-Trimethylpyridine N-oxide (179 mg, 1.3 mmol, 1 eq) and alkyl p-toluenesulfonate (400 mg, 1.44 mmol, 1.1 eq) were stirred in 1 mL of acetonitrile at 80° C. overnight. The reaction solvent was evaporated under reduced pressure, and the crude product was recrystallized twice from a solution of dichloromethane (5 mL) and diethyl ether (50 mL) at −20° C. to give pyridine nitrogen oxide p-toluenesulfonate.

[0038] Compound 2-1: (2,4,6-trimethyl-1-((4-methylpentyl)oxy)pyridin-1-ium 4-methylbenzenesulfonate), the structure is shown below:

[0039]

[0040] The compound 2-1 prepared by the above preparation method has a yield of (78%). The product was characterized, and the characterization results are as follows:

[0041] 1 H NMR (400MHz, CDCl3) δ7.60-7.53(m,2H),7.50(s,2H),7.03-6.96(m,2H),4.33(t,J=6.4Hz,2H),2.70(s,6H),2.38(s,3H) ,2.24(s,3H),1.75(ddt,J=10.5,8.1,6.4Hz,2H),1.52(dp,J=13.3,6.6Hz,1H),1.32-1.22(m,2H),0.84(d,J=6.6Hz,6H);

[0042] 13 C{1H}NMR (101MHz, CDCl3) δ157.5,151.7,144.5,138.6,129.0,128.3,125.9,80.4,34.4,27.8,25.7,22.3,21.6,21.2,17.5.

[0043] Compound 2-2: 1-(3-cyclopentylpropoxy)-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate, the structure is shown below:

[0044]

[0045] Compound 2-2 was prepared by the above preparation method with a product yield of 69%. The product was characterized, and the characterization results are as follows:

[0046] Melting point: 101-106°C;

[0047] 1 H NMR (400MHz, CDCl3) δ7.64-7.57(m,2H),7.52(s,2H),7.07-7.00(m,2H),4.40(t,J=6.4Hz,2H),2.74(s,6H),2.43( s,3H),2.27(s,3H),1.84-1.68(m,5H),1.65-1.54(m,2H),1.54-1.47(m,2H),1.47-1.38(m,2H),1.11-0.98(m,2H);

[0048] 13 C{1H}NMR(101MHz, CDCl3)δ157.5,151.7,144.3,138.7,129.0,128.3,125.9,80.4,39.8,32.5,31.9,27.1,25.1,21.7,21.2,17.6;

[0049] IR(KBr):ν(cm -1 )2937,1478,1373,1188,814;

[0050] HRMS(ESI):C 23 H 32 NO4S[M] + Calculated value: 248.2009, tested value: 248.2010.

[0051] Compound 2-3: 1-(2-cyclopentylethoxy)-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate, the structure is shown below:

[0052]

[0053] Compound 2-3 was prepared by the above preparation method with a yield of 73%. The product was characterized, and the characterization results are as follows:

[0054] Melting point: 85-90℃;

[0055] 1 H NMR (400MHz, CDCl3) δ7.61-7.54(m,2H),7.51(s,2H),7.04-6.97(m,2H),4.35(t,J=6.6Hz,2H),2.71(s,6H),2.40( s,3H),2.24(s,3H),1.94-1.82(m,1H),1.81-1.71(m,4H),1.63-1.53(m,2H),1.52-1.43(m,2H),1.14-1.02(m,2H);

[0056] 13 C{1H}NMR(101MHz, CDCl3)δ157.5,151.6,144.4,138.6,129.0,128.3,125.9,79.7,36.2,33.8,32.7,25.0,21.6,21.2,17.5;

[0057] IR(KBr):ν(cm -1 )2946,1481,1382,1186,818;

[0058] HRMS(ESI)C 22 H 31 NO4S[M] + Calculated value: 234.1852, Calculated value: 234.1853.

[0059] Compound 2-4: 1-butoxy-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate, the structure is shown below:

[0060]

[0061] Compound 2-4 was prepared by the above preparation method with a yield of 79%. The product was characterized, and the characterization results are as follows:

[0062] Melting point: 85-90℃;

[0063] 1H NMR (400MHz, CDCl3) δ7.63-7.50(m,2H),7.47(s,2H),7.09-6.94(m,2H),4.35(t,J=6.4Hz,2H),2.69(s,6H),2. 39(s,3H),2.24(s,3H),1.73(ddt,J=9.3,8.0,6.4Hz,2H),1.43(dq,J=14.8,7.4Hz,2H),0.91(t,J=7.4Hz,3H);

[0064] 13 C{1H}NMR (101MHz, CDCl3) δ157.5,151.7,144.2,138.8,129.0,128.3,125.9,79.9,29.8,21.6,21.2,18.9,17.5,13.8;

[0065] IR(KBr):ν(cm -1 )2957,1481,1380,1194,821;

[0066] HRMS(ESI)C 19 H 27 NO4S[M] + Calculated value: 194.1539, Calculated value: 194.1538.

[0067] Compound 2-5: 2,4,6-trimethyl-1-pentyloxypyridin-1-ium 4-methylbenzenesulfonate, the structure of which is shown below:

[0068]

[0069] Compound 2-5 was prepared by the above preparation method with a yield of 73%. The product was characterized, and the characterization results are as follows:

[0070] Melting point: 93-98°C;

[0071] 1 H NMR (400MHz, CDCl3) δ7.67-7.55(m,2H),7.51(s,2H),7.11-6.98(m,2H),4.39(t,J=6.4Hz,2H),2.73(s,6H),2.4 3(s,3H),2.27(s,3H),1.78(dq,J=9.2,6.6Hz,2H),1.45-1.38(m,2H),1.38-1.30(m,2H),0.89(t,J=7.1Hz,3H);

[0072] 13C{1H}NMR(101MHz, CDCl3)δ157.5,151.7,144.2,138.7,129.0,128.3,125.9,80.2,27.6,27.5,22.4,21.7,21.2,17.5,13.8;

[0073] IR(KBr):ν(cm -1 )2957,1481,1382,1194,824;

[0074] HRMS(ESI)C 20 H 28 NO4S[M] + Calculated value: 208.1696, Calculated value: 208.1695.

[0075] Example 2

[0076] This embodiment relates to the synthesis of seven-membered ether compounds, and the synthesis method is as follows:

[0077]

[0078] The specific preparation method is as follows:

[0079] Under magnetic stirring, fac-Ir(ppy)3 (0.004 mmol) and the compound represented by formula (II) (0.2 mmol) were added to a Schlenk tube, and the atmosphere was replaced with nitrogen. The compound represented by formula (III) (0.3 mmol) was dissolved in a solvent and then injected into the above reaction vessel. The reaction was carried out under a 22W blue light lamp for 2.5 hours. The solvent was removed by vacuum concentration, and the residue was purified by silica gel column chromatography using a 30:1 ratio of petroleum ether to ethyl acetate as the eluent to obtain a colorless oil.

[0080] Compound 4-1: Preparation of (E)-4,4-dimethyl-2-phenylvinyloxane, the structure of which is shown below:

[0081]

[0082] Compound 4-1 prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 1-phenylbutadiene, has a product yield of 78%. The product was characterized, and the characterization results are as follows:

[0083] 1H NMR (400MHz, CDCl3) δ7.39-7.35(m,2H),7.33-7.27(m,2H),7.24-7.18(m,1H),6.54(dd,J=15.9,1.5Hz,1H),6.20(dd,J=15.9,5.5Hz,1H),4.29-4. 19(m,1H),3.87(ddd,J=12.2,8.3,4.1Hz,1H),3.73(ddd,J=12.1,5.7,4. 3Hz,1H),1.85-1.66(m,3H),1.62-1.50(m,3H),1.08(s,3H),1.00(s,3H);

[0084] 13 C{1H}NMR(101MHz, CDCl3)δ137.2,132.0,128.5,128.5,127.3,126.4,75.4,68.1,48.9,40.8,33.1,32.9,26.6,26.6;

[0085] IR(KBr):ν(cm -1 )2954,1371,1242,747,693;

[0086] HRMS(ESI)C 16 H 22 O[M+H] + Calculated value: 231.1743, tested value: 231.1734.

[0087] Compound 4-2: (E)-4,4-dimethyl-2-(2-(thiophene-2-vinyl)oxane, the structure is shown below:

[0088]

[0089] Compound 4-2 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 2-(buta-1,3-dienyl)thiophene. The product yield was 72%. The product was characterized, and the characterization results are as follows:

[0090] 1H NMR (400MHz, CDCl3) δ7.15-7.08(m,1H),6.97-6.89(m,2H),6.67(dd,J=15.7,1.6Hz,1H),6.03(dd,J=15.7,5.3Hz,1H),4.25-4.15(m,1H) ,3.85(ddd,J=12.3,8.3,4.1Hz,1H),3.70(ddd,J=12.1,5.6,4.2Hz,1H),1.83-1.61(m,3H),1.60-1.47(m,3H),1.06(s,3H),0.99(s,3H);

[0091] 13 C{1H}NMR(101MHz, CDCl3)δ142.5,131.8,127.3,125.3,123.8,121.8,74.9,68.0,48.7,40.8,33.1,32.9,26.6,26.5;

[0092] IR(KBr):ν(cm -1 )2948,1467,1180,739,693;

[0093] HRMS(ESI)C 14 H 20 OS[M+Na] + Calculated value: 259.1127, tested value: 259.1119.

[0094] Compound 4-3: (E)-4,4-dimethyl-2-(4-(trifluoromethyl)phenyl)oxane, the structure of which is shown below:

[0095]

[0096] Compound 4-3 prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 1-(buta-1,3-dienyl)-4-(trifluoromethyl)benzene, has a product yield of 63%. The product was characterized, and the characterization results are as follows:

[0097] 1H NMR (400MHz, CDCl3) δ7.54(d,J=8.0Hz,2H),7.45(d,J=8.0Hz,2H),6.57(d,J=15.9Hz,1H),6.28(dd,J=16.0,5.2Hz,1H),4.30-4.21(m,1H ),3.88(ddd,J=12.3,8.2,4.2Hz,1H),3.73(ddd,J=12.2,4.9,4.9Hz,1H),1.85-1.64(m,3H),1.64-1.50(m,3H),1.07(s,3H),1.00(s,3H);

[0098] 13 C{1H}NMR(101MHz,CDCl3)δ140.8,134.8,129.0(q,J=32.2Hz),127.1,126.5,125.4 (q, J=3.9Hz), 124.3 (q, J=272.0Hz), 75.1, 68.2, 48.8, 40.7, 33.1, 32.8, 26.6, 26.5;

[0099] 19 F NMR (376MHz, CDCl3) δ-62.44 (s, 3F);

[0100] IR(KBr):ν(cm -1 )2949,1459,1178,745,724;

[0101] HRMS(ESI)C 17 H 21 F3O[M+Na] + Calculated value: 321.1437, tested value: 321.1430.

[0102] Compound 4-4: (E)-2-(4-bromostyryl)-4,4-dimethyloxane, the structure of which is shown below:

[0103]

[0104] Compound 4-4 was prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 1-bromo-4-(buta-1,3-dienyl)benzene. The product yield was 68%. The product was characterized, and the characterization results are as follows:

[0105] 1H NMR (400MHz, CDCl3) δ7.44-7.38(m,2H),7.25-7.19(m,2H),6.47(dd,J=15.9,1.6Hz,1H),6.18(dd,J=15.9,5.4Hz,1H),4.26-4.17(m,1H) ,3.86(ddd,J=12.3,8.2,4.2Hz,1H),3.71(ddd,J=12.1,5.7,4.2Hz,1H),1.85-1.62(m,3H),1.61-1.48(m,3H),1.06(s,3H),0.99(s,3H);

[0106] 13 C{1H}NMR(101MHz,CDCl3)δ136.2,132.9,131.6,127.9,127.3,121.0,75.2,68.2,48.8,40.7,33.1,32.9,26.6,26.5;

[0107] IR(KBr):ν(cm -1 )2953,1463,1184,845,800;

[0108] HRMS(ESI)C 16 H 21 BrO[M+Na] + Calculated value: 333.0648, tested value: 333.0644.

[0109] Compound 4-5: (E)-5-(2-(4,4-dimethyloxepan-2-yl)vinyl)benzo[d][1,3]dioxole, the structure of which is shown below:

[0110]

[0111] Compound 4-5 was prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 5-(buta-1,3-dienyl)benzo[d][1,3]dioxolane. The product yield was 78%. The product was characterized, and the characterization results are as follows:

[0112] 1H NMR (400MHz, CDCl3) δ6.90 (d, J=1.7Hz, 1H), 6.79 (dd, J=8.0, 1.7Hz, 1H), 6.73 (d ,J=8.0Hz,1H),6.44(dd,J=15.9,1.5Hz,1H),6.02(dd,J=15.9,5.6Hz,1H),5.93( s,2H),4.24-4.15(m,1H),3.85(ddd,J=12.2,8.2,4.2Hz,1H),3.70(ddd,J=12.1, 5.7,4.3Hz,1H),1.83–1.61(m,3H),1.59-1.48(m,3H),1.06(s,3H),0.99(s,3H);

[0113] 13 C{1H}NMR(101MHz, CDCl3)δ147.9,146.9,131.7,130.3,128.2,120.9,108.2,105.7,101.0,75.4,68.1,49.0,40.7,33.1,32.9,26.6,26.6;

[0114] IR(KBr):ν(cm -1 )2949,1492,1191,795,738;

[0115] HRMS(ESI)C 17 H 22 O3[M+Na] + Calculated value: 275.1642, tested value: 275.1644.

[0116] Compound 4-6: (E)-4,4-dimethyl-2-(1-phenylpropen-2-yl)oxane, the structure of which is shown below:

[0117]

[0118] Compound 4-6 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was (2-methylbuta-1,3-dienyl)benzene. The product yield was 67%. The product was characterized, and the characterization results are as follows:

[0119] 1H NMR (400MHz, CDCl3) δ7.35-7.26(m,3H),7.25(s,1H),7.23-7.12(m,1H),6.48(s,1H),4.00(d,J=10.0Hz,1H),3.93(ddd,J=12.0,7.4, 4.7Hz,1H),3.72(ddd,J=12.0,6.0,4.3Hz,1H),1.85(s,3H),1.75(qd,J=9.9,6.1Hz,3H),1.61-1.52(m,3H),1.06(s,3H),1.01(s,3H);

[0120] 13 C{1H}NMR(101MHz, CDCl3)δ140.3,138.0,129.0,128.0,126.1,123.8,80.2,69.5,48.1,40.4,32.9,32.7,27.3,26.3,14.7;

[0121] IR(KBr):ν(cm -1 )2951,1446,1186,751,696;

[0122] HRMS(ESI)C 17 H 24 O[M+H] + Calculated value: 245.1900, tested value: 245.1900.

[0123] Compound 4-7: (E)-3,4,4-trimethyl-2-phenylvinyloxane, the structure of which is shown below:

[0124]

[0125] Compound 4-7 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was penta-1,3-dien-1-ylbenzene. The product yield was 13%. The product was characterized, and the characterization results are as follows:

[0126] 1H NMR (400MHz, CDCl3) δ7.42-7.35(m,2H),7.33-7.28(m,2H),7.25-7.19(m,1 H),6.50(d,J=15.8Hz,1H),6.23(dd,J=15.8,7.3Hz,1H),3.82-3.72(m,2H) ,3.67(dt,J=12.0,5.0Hz,1H),1.88-1.75(m,1H),1.69(m,1H),1.63-1.58( m,2H),1.56-1.50(m,1H),1.00(s,3H),0.94(s,3H),0.80(d,J=7.0Hz,3H);

[0127] 13 C{1H}NMR(101MHz, CDCl3)δ137.20,130.98,130.47,128.50,127.36,126.43,82.59,67.10,47.25,41.09,35.93,31.47,26.07,21.19,14.05;

[0128] IR(KBr):ν(cm -1 )2954,1450,1156,748,690;

[0129] HRMS(ESI)C 17 H 24 O[M+Na] + Calculated value: 267.1719, tested value: 267.1710.

[0130] Compound 4-8: (E)-2-(2-methoxyphenylvinyl)-4,4-dimethyloxane, the structure of which is shown below:

[0131]

[0132] Compound 4-8 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 1-(buta-1,3-dienyl)-2-methoxybenzene. The product yield was 75%. The product was characterized, and the characterization results are as follows:

[0133] 1H NMR (400MHz, CDCl3) δ7.42 (dd, J=7.7, 1.7Hz, 1H), 7.20 (td, J=7.8, 1.7Hz, 1H), 6.90 ( t,J=7.5Hz,1H),6.86(s,1H),6.83(d,J=9.1Hz,1H),6.23(dd,J=16.0,5.9Hz,1H),4.2 9-4.19(m,1H),3.88(td,J=8.1,4.0Hz,1H),3.84(s,3H),3.72(dt,J=12.1,4.9Hz,1H ),1.86-1.64(m,3H),1.64-1.56(m,2H),1.55-1.45(m,2H),1.07(s,3H),1.00(s,3H);

[0134] 13 C{1H}NMR(101MHz, CDCl3)δ156.7,132.6,128.3,126.8,126.2,123.4,120.6,110.8,76.0,68.0,55.4,49.0,40.7,33.1,33.0,26.7,26.6;

[0135] IR(KBr):ν(cm -1 )2953,1449,1145,783,680;

[0136] HRMS(ESI)C 17 H 24 O2[M+Na] + Calculated value: 283.1669, tested value: 283.1671.

[0137] Compound 4-9: (E)-4,4-dimethyl-2-(4-phenylbut-1-enyl)oxane, the structure of which is shown below:

[0138]

[0139] Compound 4-9 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was hexa-3,5-dienylbenzene. The product yield was 18%. The product was characterized, and the characterization results were as follows:

[0140] 1H NMR (400MHz, CDCl3) δ7.31-7.26(m,2H),7.21-7.14(m,3H),5.64(dtd,J=15.4,6. 5,1.2Hz,1H),5.49(ddt,J=15.4,5.9,1.4Hz,1H),4.05-3.95(m,1H),3.80(ddd,J =12.2,8.1,4.2Hz,1H),3.64(ddd,J=12.1,5.8,4.2Hz,1H),2.73-2.64(m,2H),2. 37-2.28(m,2H),1.78-1.58(m,3H),1.53-1.39(m,3H),1.01(s,3H),0.96(s,3H);

[0141] 13 C{1H}NMR(101MHz, CDCl3)δ142.0,132.8,129.0,128.5,128.3,125.8,75.5,68.0,49.0,40.8,35.7,34.2,33.0,32.9,26.7,26.6;

[0142] IR(KBr):ν(cm -1 )2951,1457,1180,742,698;

[0143] HRMS(ESI)C 18 H 26 O[M+Na] + Calculated value: 259.2056, tested value: 259.2047.

[0144] Compound 4-10: (E)-2-(2-([1,1'-biphenyl]-4-vinyl)-4,4-dimethyloxane, the structure of which is shown below:

[0145]

[0146] Compound 4-10 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 4-(buta-1,3-dienyl)-1,1'-biphenyl. The product yield was 57%. The product was characterized, and the characterization results are as follows:

[0147] 1H NMR(400MHz, CDCl3)7.60(d,J=7.7Hz,2H),7.55(d,J=7.9Hz,2H),7.44(t,J=7 .6Hz,4H),7.34(t,J=7.3Hz,1H),6.58(d,J=15.8Hz,1H),6.25(dd,J=15.9,5.5 Hz,1H),4.31-4.22(m,1H),3.89(ddd,J=12.4,8.1,4.1Hz,1H),3.74(dt,J=11. 2,5.0Hz,1H),1.85-1.66(m,3H),1.64-1.51(m,3H),1.09(s,3H),1.01(s,3H);

[0148] 13 C{1H}NMR(101MHz, CDCl3)δ140.8,140.0,136.3,132.2,128.8,128.0,127.2,127.2,126.9,126.8,75.4,68.1,48.9,40.8,33.2,32.9,26.6,26.6;

[0149] IR(KBr):ν(cm -1 )2953,1488,1116,723,692;

[0150] HRMS(ESI)C 22 H 26 O[M+H] + Calculated value: 307.2056, tested value: 307.2047.

[0151] Compound 4-11: (E)-2-(2-(Benzo[b]thiophen-2-yl)vinyl)-4,4-dimethyloxane, the structure of which is shown below:

[0152]

[0153] Compound 4-11 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 2-(buta-1,3-dienyl)benzothiophene. The product yield was 65%. The product was characterized, and the characterization results are as follows:

[0154] 1H NMR (400MHz, CDCl3) δ7.77-7.71(m,1H),7.68-7.64(m,1H),7.32-7.24(m,2H) ,7.11(s,1H),6.78(ddd,J=15.7,1.7,0.7Hz,1H),6.12(dd,J=15.6,5.0Hz,1H) ,4.30-4.21(m,1H),3.88(ddd,J=12.3,8.3,4.1Hz,1H),3.73(ddd,J=12.1,5. 6,4.3Hz,1H),1.85-1.65(m,3H),1.63-1.50(m,3H),1.07(s,3H),1.01(s,3H);

[0155] 13 C{1H}NMR(101MHz,CDCl3)δ142.6,140.2,138.8,134.6,124.4,124.3,123.3 ,122.4,122.4,122.2,74.8,68.1,48.6,40.7,33.1,32.9,29.7,26.6,26.5;

[0156] IR(KBr):ν(cm -1 )2949,1487,1119,1006,759,692;

[0157] HRMS(ESI)C 18 H 22 OS[M+H] + Calculated value: 287.1464, tested value: 287.1459.

[0158] Compound 4-12: (E)-4,4-dimethyl-2-(4-methylphenyl)oxane, the structure of which is shown below:

[0159]

[0160] Compound 4-12 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 1-(buta-1,3-dienyl)-4-methylbenzene. The product yield was 74%. The product was characterized, and the characterization results are as follows:

[0161] 1H NMR (400MHz, CDCl3) δ7.29–7.22(m,2H),7.13–7.06(m,2H),6.49(dd,J=15.9,1.4Hz,1H),6.14(dd,J=15.9,5.6Hz,1H),4.26–4.17(m,1H),3.86 (ddd,J=12.3,8.3,4.1Hz,1H),3.71(ddd,J=12.1,5.7,4.3Hz,1H),2.32 (s,3H),1.84–1.62(m,3H),1.60–1.46(m,3H),1.06(s,3H),0.99(s,3H);

[0162] 13 C{1H}NMR(101MHz, CDCl3)δ137.0,134.4,131.0,129.2,128.4,126.3,75.5,68.1,49.0,40.8,33.1,32.9,26.6,26.6,21.2;

[0163] IR(KBr):ν(cm -1 )2953,1470,1180,738,699;

[0164] HRMS(ESI)C 17 H 24 O[M+Na] + Calculated value: 269.2240, tested value: 269.2244.

[0165] Compound 4-13: (E)-2,4,4-trimethyl-2-phenylvinyloxane, the structure of which is shown below:

[0166]

[0167] Compound 4-13 was prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is (3-methylbuta-1,3-dien-1-yl)benzene. The product yield was 60%. The product was characterized, and the characterization results are as follows:

[0168] 1H NMR (400MHz, CDCl3) δ7.38(d,J=7.7Hz,2H),7.31(t,J=7.5Hz,2H),7.21(t,J=7.3Hz,1H),6.49(d,J=16.2Hz,1H),6.23(d,J=16.2Hz,1H),3.78–3. 69(m,1H),3.69–3.59(m,1H),1.85(d,J=15.0Hz,1H),1.73(qd,J=13.5,6 .6Hz,3H),1.40(p,J=3.9Hz,2H),1.33(s,3H),1.09(s,3H),1.01(s,3H);

[0169] 13 C{1H}NMR(101MHz, CDCl3)δ138.8,137.6,128.5,127.0,126.3,126.0,77.6,64.3,51.0,44.0,34.9,30.5,29.6,29.5,28.3;

[0170] IR(KBr):ν(cm -1 )2946,1447,1096,745,690;

[0171] HRMS(ESI)C 17 H 24 O[M+Na] + Calculated value: 267.1719, tested value: 267.1710.

[0172] Compound 4-14: 2-((4-methoxyphenyl)ethynyl)-4,4-dimethyloxane, the structure is shown below:

[0173]

[0174] Compound 4-14 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 1-(but-3-yn-1-enyl)-4-methoxybenzene. The product yield was 69%. The product was characterized, and the characterization results are as follows:

[0175] 1H NMR (400MHz, CDCl3) δ7.41–7.32(m,2H),6.85–6.75(m,2H),4.57(dd,J=10.4,3.8Hz,1H),3.88(ddd,J=12.4,8.8,3.7Hz,1H),3.79( s,3H),3.72(dt,J=12.3,4.6Hz,1H),1.98(dd,J=14.9,10.4Hz,1H),1.86–1.61(m,3H),1.52–1.46(m,2H),1.05(s,3H),1.01(s,3H);

[0176] 13 C{1H}NMR(101MHz, CDCl3)δ159.5,133.1,115.1,113.8,88.5,84.0,67.3,66.3,55.3,49.2,41.0,33.5,32.7,26.7,26.0;

[0177] IR(KBr):ν(cm -1 )2951,1464,1364,1101,830;

[0178] HRMS(ESI)C 17 H 22 O2[M+Na] + Calculated value: 281.1512, tested value: 281.1516.

[0179] Compound 4-15: 4,4-dimethyl-2-(p-tolylethynyl)oxane, the structure of which is shown below:

[0180]

[0181] Compound 4-15 was prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 1-(but-3-yn-1-enyl)-4-methylbenzene. The product yield was 50%. The product was characterized, and the characterization results are as follows:

[0182] 1H NMR (400MHz, CDCl3) δ7.35-7.29(m,2H),7.09(d,J=7.9Hz,2H),4.58(dd,J=10.4,3.9Hz,1H),3.89(ddd,J=12.4,8.9,3.7Hz,1H),3.73(d dd,J=12.4,5.3,4.1Hz,1H),2.33(s,3H),1.99(dd,J=14.9,10.4Hz,1H),1.86-1.59(m,3H),1.53-1.46(m,2H),1.06(s,3H),1.02(s,3H);

[0183] 13 C{1H}NMR(101MHz, CDCl3)δ138.2,131.6,129.0,119.9,89.2,84.3,67.3,66.2,49.2,41.0,33.6,32.7,26.7,26.0,21.5;

[0184] IR(KBr):ν(cm -1 )2960,1473,1368,1118,818;

[0185] HRMS(ESI)C 17 H 22 O[M+Na] + Calculated value: 243.1743, measured value: 243.1734.

[0186] Compound 4-16: 2-((4-bromophenyl)ethynyl)-4,4-dimethyloxane, the structure of which is shown below:

[0187]

[0188] Compound 4-16 was prepared by the above preparation method, wherein the compound of formula (II) was compound 2-1 prepared in Example 1, and the compound of formula (III) was 1-bromo-4-(but-3-yn-1-enyl)benzene. The product yield was 53%. The product was characterized, and the characterization results are as follows:

[0189] 1H NMR (400MHz, CDCl3) δ7.45-7.39(m,2H),7.30-7.26(m,2H),4.56(dd,J=10.5,3.8Hz,1H),3.87(ddd,J=12.5,8.9,3.7Hz,1H),3.73(d dd,J=12.3,5.3,4.2Hz,1H),1.97(dd,J=14.9,10.4Hz,1H),1.85-1.62(m,3H),1.50(dd,J=7.5,4.8Hz,2H),1.05(s,3H),1.01(s,3H);

[0190] 13 C{1H}NMR(101MHz,CDCl3)δ133.2,131.5,122.4,122.0,91.1,83.1,67.4,66.2,49.0,41.0,33.6,32.7,26.7,25.9;

[0191] IR(KBr):ν(cm -1 )2956,1484,1384,1070,823;

[0192] HRMS(ESI)C 17 H 22 O[M+H] + Calculated values: 307.0692, 309.0672, tested values: 307.0695, 309.0670.

[0193] Compound 4-17: (E)-2-(3-fluorophenylvinyl)-4,4-dimethyloxane, the structure of which is shown below:

[0194]

[0195] Compound 4-17 prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 1-(buta-1,3-dien-1-yl)-3-fluorobenzene, the product yield is 69%, and the product is characterized, and the characterization results are as follows:

[0196] 1H NMR (400MHz, CDCl3) δ7.27-7.19(m,1H),7.10(dt,J=7.7,1.2Hz,1H),7.05(dt,J=10. 3,2.1Hz,1H),6.89(td,J=8.3,2.3Hz,1H),6.50(dd,J=16.0,1.5Hz,1H),6.18(dd,J=1 5.9,5.3Hz,1H),4.27-4.17(m,1H),3.85(ddd,J=12.2,8.2,4.1Hz,1H),3.71(ddd,J=1 2.1,5.7,4.3Hz,1H),1.85-1.62(m,3H),1.60-1.48(m,3H),1.06(s,3H),0.99(s,3H);

[0197] 13 C{1H}NMR(101MHz, CDCl3)δ163.1(d,J=244.9Hz),139.7(d,J=7.6Hz),133.5,129.9(d,J=8.4Hz),127.4,127.3 ,122.3(d,J=2.7Hz),114.0(d,J=21.4Hz),112.8(d,J=21.6Hz),75.1,68.1,48.8,40.7,33.1,32.9,26.6,26.6;

[0198] 19 F NMR (376MHz, CDCl3) δ-113.81 (s, 1F);

[0199] IR(KBr):ν(cm -1 )2953,1463,1103,751,701;

[0200] HRMS(ESI)C 16 H 21 FO[M+Na] + Calculated value: 271.1469, tested value: 271.1473.

[0201] Compound 4-18: (E)-2-(4-(tert-butyl)phenylvinyl)-4,4-dimethyloxane, the structure of which is shown below:

[0202]

[0203] Compound 4-18 was prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 1-(buta-1,3-dienyl)-4-(tert-butyl)benzene. The product yield was 73%. The product was characterized, and the characterization results are as follows:

[0204] 1 H NMR (400MHz, CDCl3) δ7.37-7.27(m,4H),6.51(dd,J=15.9,1.5Hz,1H),6.16(dd,J=15.9,5.5Hz,1H),4.28-4.19(m,1H),3.86(ddd,J=1 2.3,8.3,4.1Hz,1H),3.72(ddd,J=12.1,5.7,4.2Hz,1H),1.85-1.65(m,3H),1.63-1.50(m,3H),1.32(s,9H),1.07(s,3H),1.00(s,3H);

[0205] 13 C{1H}NMR (101MHz, CDCl3) δ150.3,134.4,131.3,128.2,126.1,125.4,75.5,68.0,48.9,40.8,34.5,33.1,32.9,31.3,26.6,26.6;

[0206] IR(KBr):ν(cm -1 )2953,1464,1108,738,703;

[0207] HRMS(ESI)C 20 H 30 O[M+H] + Calculated value: 287.2369, tested value: 287.2360.

[0208] Compound 4-19: (E)-4,4-dimethyl-2-(2-(naphthyl)vinyl)oxane, the structure is shown below:

[0209]

[0210] Compound 4-19 prepared by the above preparation method, wherein the compound of formula (II) is compound 2-1 prepared in Example 1, and the compound of formula (III) is 2-(buta-1,3-dienyl)naphthalene, the product yield is 57%, and the product is characterized, and the characterization results are as follows:

[0211] 1H NMR (400MHz, CDCl3) δ8.21-8.11(m,1H),7.85(dd,J=7.9,1.7Hz,1H),7.77(dt,J=8.2,1.1Hz,1H) ,7.59(dt,J=7.2,1.0Hz,1H),7.54-7.47(m,2H),7.44(dd,J=8.2,7.2Hz,1H),7.31(dd,J=15.6,1. 9Hz,1H),6.23(dd,J=15.6,5.3Hz,1H),4.43-4.33(m,1H),3.94(ddd,J=12.3,8.4,3.9Hz,1H),3. 80(ddd,J=12.1,5.6,4.2Hz,1H),1.92-1.63(m,4H),1.59-1.53(m,2H),1.13(s,3H),1.04(s,3H);

[0212] 13 C{1H}NMR(101MHz,CDCl3)δ135.3,135.1,133.6,131.3,128.5,127.6,125.9,12 5.7,125.6,125.6,124.0,123.7,75.5,68.0,48.9,40.9,33.2,33.0,26.7,26.6;

[0213] IR(KBr):ν(cm -1 )2951,1464,1119,734,703;

[0214] HRMS(ESI)C 20 H 24 O[M+H] + Calculated value: 281.1900, tested value: 281.1891.

[0215] Compound 4-20: (E)-7-phenylvinyl-8-oxaspiro[4.6]undecane, the structure of which is shown below:

[0216]

[0217] Compound 4-20 prepared by the above preparation method has a dr ratio of 1:7:10, wherein the compound of formula (II) is 1-(3-cyclopentylpropoxy)-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate, and the compound of formula (III) is 1-phenylbutadiene. The product yield is 63%. The product was characterized, and the characterization results are as follows:

[0218] 1H NMR (400MHz, CDCl3) δ7.39-7.34(m,2H),7.32-7.27(m,2H),7.23-7.18(m,1H),6.54(dd,J=16.0,1.5Hz,1H),6.21(dd,J=15.9,5.5Hz,1H),4.26-4.18 (m,1H),3.87(ddd,J=12.1,8.2,4.7Hz,1H),3.75(dt,J=12.1,5.0Hz,1H),1 .85-1.68(m,4H),1.68-1.63(m,3H),1.63-1.53(m,5H),1.52-1.43(m,2H);

[0219] 13 C{1H}NMR(101MHz,CDCl3)δ137.2,132.0,128.5,128.5,127.3,126.4,76.0,67.8,47.6,45.2,42.4,38.7,35.9,27.1,24.4,23.8;

[0220] IR(KBr):ν(cm -1 )2922,1447,1130,739,693;

[0221] HRMS(ESI)C 18 H 24 O[M+H] + Calculated value: 257.1900, tested value: 257.1905.

[0222] Compound 4-21: (E)-2-phenylethynyl lotahydro-2H-cyclopenta[d]oxazepine, the structure is shown below:

[0223]

[0224] Compound 4-21 prepared by the above preparation method, wherein the compound of formula (II) is 1-(2-cyclopentylethoxy)-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate (compound 2-3), and the compound of formula (III) is 1-phenylbutadiene, the product yield is 62%, and the product is characterized, and the characterization results are as follows:

[0225] 1H NMR (400MHz, CDCl3) δ7.42-7.35(m,3.15H),7.35-7.26(m,3.13H),7.25-7.19(m,1.54H),6.61-6.51(m,1.55H),6.29-6.21(m ,1.54H),4.30(qd,J=6.5,1.5Hz,0.51H),4.22-4.15(m,0.94H),4.13(ddd,J=12.4,4.3,2.1Hz,0.57H),3.92(ddd,J=12.3,8.1 ,5.6Hz,0.99H),3.78(dt,J=12.5,5.5Hz,0.97H),3.50(td,J=12.3,2.1Hz,0.57H),2.09-1.99(m,2.50H),1.96-1.83(m,3.95H ),1.82-1.72(m,1.45H),1.71-1.54(m,5.87H),1.53-1.39(m,2.50H),1.30(dd,J=10.3,7.9Hz,1.60H),1.26-1.19(m,1.22H);

[0226] 13 C{1H}NMR(101MHz,CDCl3)δ137.20,132.00,131.57,128.82,128.49,128.47,127.30,127.28,126.40,80.01,79.70 ,70.91,66.90,46.60,45.40,45.30,42.30,41.33,39.64,37.69,34.72,34.37,33.98,33.88,33.75,23.76,23.40;

[0227] IR(KBr):ν(cm -1 )2946,1452,1118,748,692;

[0228] HRMS(ESI)C 17 H 22 O[M+Na] + Calculated value: 265.1563, tested value: 265.1554.

[0229] Compound 4-22: (E)-2-phenylvinyloxane, the structure of which is shown below:

[0230]

[0231] Compound 4-22 prepared by the above preparation method, wherein the compound of formula (II) is 1-butoxy-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate (compound 2-4), and the compound of formula (III) is 1-phenylbutadiene, the product yield is 23%, and the product is characterized, and the characterization results are as follows:

[0232] 1 H NMR (400MHz, CDCl3) δ7.41-7.34(m,2H),7.30(dd,J=8.5,6.7Hz,2H),7.25-7.16(m,1H),6.56(dd,J=16.0,1.5Hz,1H),6.24(dd,J=16.0,5.5Hz,1H),4 .27-4.18(m,1H),3.96-3.85(m,1H),3.68(ddd,J=12.2,7.3,3.8Hz,1H),2 .01-1.90(m,1H),1.87-1.75(m,2H),1.75-1.65(m,3H),1.65-1.57(m,2H);

[0233] 13 C{1H}NMR(101MHz,CDCl3)δ137.2,131.8,128.9,128.5,127.3,126.4,79.4,67.9,36.0,31.2,27.2,25.4;

[0234] IR(KBr):ν(cm -1 )2925,1447,1131,731,693;

[0235] HRMS(ESI)C 14 H 18 O[M+H] + Calculated value: 203.1430, tested value: 203.1421.

[0236] Compound 4-23: (E)-4-methyl-2-phenylvinyloxane, the structure of which is shown below:

[0237]

[0238] Compound 4-23 prepared by the above preparation method has a dr ratio of 1:1.3, wherein the compound of formula (II) is 2,4,6-trimethyl-1-(pentyloxy)pyridin-1-ium 4-methylbenzenesulfonate (compound 2-5), and the compound of formula (III) is 1-phenylbutadiene. The product yield is 57%. The product was characterized, and the characterization results are as follows:

[0239] 1H NMR (400MHz, CDCl3) δ7.43-5.35(m,3.54H),7.31(t,J=7.5Hz,3.51H),7.25-7.20(m,1.70H),6.58(ddd,J=16.1,6.4 ,1.5Hz,1.72H),6.24(dt,J=15.9,5.8Hz,1.74H),4.34(qd,J=5.9,1.5Hz,0.75H),4.26-4.17(m,1.01H),4.01(dtd,J =12.3,3.9,1.5Hz,0.79H),3.92-3.76(m,2.05H),3.59(ddd,J=12.5,7.4,5.2Hz,0.78H),2.07-1.93(m,0.84H),1.9 2-1.67(m,9.07H),1.54-1.43(m,0.98H),1.43-1.30(m,2.11H),1.02(d,J=1.8Hz,2.53H),1.01(d,J=2.1Hz,2.44H);

[0240] 13 C{1H}NMR(101MHz,CDCl3)δ131.93,131.74,128.94,128.75,128.51,127.31,127.30,126.43,126.41 ,78.01,77.64,69.39,67.24,45.16,42.95,36.22,35.05,33.63,30.72,29.79,29.06,24.03,23.25;

[0241] IR(KBr):ν(cm -1 )2922,1446,1106,751,696;

[0242] HRMS(ESI)C 15 H 20 O[M+Na] + Calculated value: 239.1406, tested value: 239.1399.

[0243] Compound 4-24: (E)-4-phenyl-2-phenylvinyloxane, the structure of which is shown below:

[0244]

[0245] Compound 4-24 prepared by the above preparation method has a dr ratio of 1:1.7, wherein the compound of formula (II) is 2,4,6-trimethyl-1-(4-phenylbutoxy)pyridin-1-ium 4-methylbenzenesulfonate, and the compound of formula (III) is 1-phenylbutadiene. The product yield is 25%. The product was characterized, and the characterization results are as follows:

[0246] 1 H NMR (400MHz, CDCl3) δ7.40-7.34(m,3.24H),7.33-7.27(m,6.40H),7.25-7.15(m,6.47H),6.61(td,J=16 .3,1.5Hz,1.54H),6.25(ddd,J=16.0,8.0,5.4Hz,1.57H),4.53-4.44(m,0.59H),4.39-4.29(m,1H),4.1 3(ddt,J=12.7,4.2,2.1Hz,0.64H),4.00-3.86(m,2.14H),3.67(ddd,J=12.8,9.9,3.2Hz,0.62H),3.13- 3.02(m,0.59H),2.96-2.84(m,1H),2.34-2.18(m,0.78H),2.16-2.05(m,1.55H),2.04-1.76(m,7.76H);

[0247] 13 C{1H}NMR(101MHz,CDCl3)δ148.79,148.26,137.11,137.06,131.38,131.25,129.39,129.07,128.52,128.51,128.49,127.38,127.36, 126.64,126.62,126.44,126.40,126.03,125.86,78.03,77.79,69.77,66.88,45.42,44.65,43.00,41.05,36.06,34.64,31.67,29.49;

[0248] IR(KBr):ν(cm -1 )2924,1447,1130,745,694;

[0249] HRMS(ESI)C 20 H 22 O[M+H] + Calculated value: 279.1743, tested value: 279.1734.

[0250] Compound 4-25: (E)-8-phenylvinyl-9-oxaspiro[5.6]dodecane, the structure is shown below:

[0251]

[0252] Compound 4-25 prepared by the above preparation method, wherein the compound of formula (II) is 1-(3-cyclohexylpropoxy)-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate, and the compound of formula (III) is 1-phenylbutadiene, has a product yield of 66%. The product was characterized, and the characterization results are as follows:

[0253] 1 H NMR (400MHz, CDCl3) δ7.40-7.34(m,2H),7.32-7.27(m,2H),7.24-7.18(m,1H),6.53(dd,J=16.0,1.4Hz,1H),6.22(dd,J=15.9,5.5Hz, 1H),4.30-4.21(m,1H),3.87(ddd,J=11.8,7.8,3.8Hz,1H),3.68(ddd,J=12.2,6.2,3.9Hz,1H),1.86-1.57(m,5H),1.56-1.27(m,11H);

[0254] 13 C{1H}NMR(101MHz, CDCl3)δ137.2,132.2,128.5,128.4,127.2,126.4,75.2,68.0,40.3,35.3,34.9,26.5,26.1,22.1,22.0;

[0255] IR(KBr):ν(cm -1 )2925,1449,1178,736,689;

[0256] HRMS(ESI)C 19 H 26 O[M+Na] + Calculated value: 293.1876, tested value: 293.1878.

[0257] Compound 4-26: (5aS,7R,9S,11R,11aS)-2-((E)-phenylvinyl)decahydro-2H-5a,9:7,11-dimethanol cyclooctyl[d]oxazepine, the structure is shown below:

[0258]

[0259] Compound 4-26 prepared by the above preparation method, wherein the compound of formula (II) is 1-(2-(3R, 5R, 7R)-adamantan-1-yl)ethoxy)-2,4,6-trimethylpyridin-1-ium 4-methylbenzenesulfonate, and the compound of formula (III) is 1-phenylbutadiene, the product yield is 60%, and the product is characterized, and the characterization results are as follows:

[0260] 1 H NMR (400MHz, CDCl3) δ7.38(d,J=7.7Hz,2H),7.30(d,J=15.0Hz,2H),7.21(t,J=7.3Hz,1H),6 .56(d,J=16.0Hz,1H),6.24(dd,J=16.0,5.5Hz,1H),4.37-4.27(m,1H),3.84-3.74(m,1H),3 .72-3.62(m,1H),2.15(dt,J=15.2,11.1Hz,1H),2.03(d,J=13.0Hz,1H),1.93(dt,J=10.3,3 .4Hz,2H),1.87-1.66(m,6H),1.64-1.40(m,6H),1.36-1.28(m,1H),1.19(d,J=12.7Hz,1H);

[0261] 13 C{1H}NMR(101MHz,CDCl3)δ137.2,131.9,128.7,128.5,127.3,126.4,78.3, 61.7,47.2,47.0,45.8,39.2,38.8,37.8,37.6,36.2,33.8,31.4,28.8,28.6;

[0262] IR(KBr):ν(cm -1 )2901,1454,1159,748,695;

[0263] HRMS(ESI)C 22 H 28 O[M+Na] + Calculated value: 331.2032, tested value: 331.2024.

[0264] The above-described embodiments are merely preferred examples for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A method for synthesizing a seven-membered ring ether compound, comprising the following steps: (1) reacting 2,4,6-trimethylpyridine N-oxide with an alkyl p-toluenesulfonate represented by formula (I) in the presence of a first solvent to obtain a pyridine N-oxide p-toluenesulfonate represented by formula (II); (2) Under visible light irradiation, the pyridine nitrogen oxide p-toluenesulfonate prepared in step (1) is subjected to a cycloaddition reaction with the conjugated diene compound represented by formula (III) in the presence of a photocatalyst and a second solvent to obtain a seven-membered cyclic ether compound represented by formula (IV); The compounds represented by the above formula (I) to formula (IV) are as follows: 、 、 、 ， Wherein, R1 is selected from -CH=CH-, -C≡C-, -(CH2)2-CH=CH-, One of the following; R2 and R3 are each selected from one of hydrogen and methyl; R4, R5, and R6 are each selected from hydrogen, alkyl, and aryl, or R4 and R5 are cyclized to form a cyclopentyl or cyclohexyl group, or R5 and R6 are cyclized to form a cyclopentyl or adamantyl group; Ar is selected from one of phenyl, 2-thienyl, 4-trifluoromethylbenzene, 4-bromophenyl, 3,4-methylenedioxyphenyl, 2-methoxyphenyl, phenethyl, 4-phenylphenyl, 2-benzothienyl, 4-methoxyphenyl, 4-tolyl, 3-fluorophenyl, 4-tert-butylbenzene and 2-naphthyl.

2. The synthesis method according to claim 1, characterized in that In step (1), the molar ratio of 2,4,6-trimethylpyridine nitrogen oxide to alkyl p-toluenesulfonate is 1:1-1.

2.

3. The synthesis method according to claim 1, wherein In step (1), the reaction temperature is 70-80 °C, and the reaction time is 8 h-12 h.

4. The synthesis method according to claim 1, characterized in that In step (2), the visible light is blue light and / or green light.

5. The synthesis method according to claim 1, characterized in that In step (2), the photocatalyst is fac-[Ir(ppy)3], 4CzIPN, [Ir(dF(Me)ppy)2(bpy)]PF6, [Ir(dF(CF3)ppy)2(bpy)]PF6, dinaphthylene or 10-phenyl-10H-phenothiazine; and the molar ratio of the photocatalyst to the conjugated diene compound is 0.01-0.03:

1.

6. The synthesis method according to claim 1, characterized in that In step (2), the molar ratio of the pyridine nitrogen oxide p-toluenesulfonate to the conjugated diene compound is 0.5-3:

1.

7. The synthesis method according to claim 1, characterized in that In step (2), the reaction temperature of the cycloaddition reaction is 0-50°C, and the reaction time is 15 min-12 h.

8. The synthesis method according to claim 1, characterized in that The first solvent and the second solvent are respectively selected from one or more of acetonitrile, N,N-diformamide, methanol, tetrahydrofuran, dichloromethane and dichloroethane.

9. The synthesis method according to claim 1, characterized in that The seven-membered ring ether compound is one of the compounds shown in the following structure: ， 。

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