(R)-4-isopropyl-3-((r)-2-methyl-5-hexenoyl)oxazolidin-2-one and use in the synthesis of components of the western hemlock borer sex pheromone

Abstract

The application discloses a kind of ( R )‑4‑isopropyl‑3‑(( R )‑2‑methyl‑5‑hexenoyl) oxazolidine‑2‑ketone and application in synthesis western hemlock looper sex pheromone component, it relates to the technical field of biological pesticide.The application utilizes ( R )‑4‑isopropyl‑3‑(( R )‑2‑methyl‑5‑hexenoyl) oxazolidine‑2‑ketone synthesis (5 R ,11 S )‑5,11‑dimethyl heptadecane, total yield can reach 18%, and (5 R ,11 S )‑5,11‑dimethyl heptadecane optical purity is greater than 99%;The application utilizes ( R )‑4‑isopropyl‑3‑(( R )‑2‑methyl‑5‑hexenoyl) oxazolidine‑2‑ketone synthesis ( S )‑7‑methyl heptadecane, total yield can reach 30%, and (5 R ,11 S )‑5,11‑dimethyl heptadecane optical purity is greater than 99%.

Description

Technical Field

[0001] This invention belongs to the field of biopesticide technology, specifically relating to (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one and its application in the synthesis of sex pheromone components of the western hemlock looper. Background Technology

[0002] 4-Isopropyl-3-(2-methyl-5-hexenoyl)oxazolidin-2-one is a commonly used chiral building block in the fields of pharmaceutical, pesticide, and materials synthesis. In 2014, Brimble and his team disclosed in a paper titled "Wadsworth, AD; Furkert, DP; Brimble, MA The Journal of Organic Chemistry 2014, 79, 11179-11193." that (S)-4-isopropyl-3-((S)-2-methyl-5-hexenoyl)oxazolidin-2-one and (R)-4-isopropyl-3-((S)-2-methyl-5-hexenoyl)oxazolidin-2-one were synthesized by reacting (S)-4-isopropyl-3-((S)-2-methyl-5-hexenoyl)oxazolidin-2-one with tributylallyltinane catalyzed by a Lewis acid catalyst of titanium tetrachloride. However, (R)-4-isopropyl-3-(( (R)-2-methyl-5-hexenoyl)oxazolidin-2-one is a compound for which this application specifically developed (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one, and prepared (5R,11S)-5,11-dimethylheptadecane (i.e., western hemlock looper sex pheromone component 1) and (S)-7-methylheptadecane (i.e., western hemlock looper sex pheromone component 2) based on (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one and its application in the synthesis of sex pheromone components of the western hemlock looper.

[0004] The technical solution of this invention is as follows:

[0005] A (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one, the structural formula of which is shown in Formula 7:

[0006]

[0007] A method for synthesizing (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one, wherein the (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one is the aforementioned (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one, and the method for synthesizing the (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one includes the following steps:

[0008] S1. Using 5-hexenoic acid as the starting material, (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one was synthesized by reacting it with (R)-4-isopropyloxazolidin-2-one.

[0009] S2, through a chiral-induced asymmetric methylation reaction, synthesizes (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one.

[0010] Preferably, step S1 includes the following specific steps:

[0011] S1-1. Under argon protection and at 0-5℃, oxalyl chloride and dimethylformamide were slowly added to a dichloromethane solution containing 5-hexenoic acid; then the temperature was raised to room temperature, the reaction was stirred for 2-4 hours, and the solvent was removed by concentration under reduced pressure to obtain a slightly yellow crude acyl chloride product.

[0012] S1-2. Under argon protection and at 0–5°C, sodium hydride was dissolved in dry tetrahydrofuran; then, a dry tetrahydrofuran solution containing (R)-4-isopropyloxazolidin-2-one was slowly added; then, the temperature was raised to 25–30°C and stirred for 2–4 hours; then, the temperature was lowered to 0–5°C, and a dry tetrahydrofuran solution containing crude acyl chloride was slowly added, and stirred at room temperature for 4–6 hours; then, the mixture was quenched, separated, extracted, washed, dried and concentrated, and finally purified by silica gel column chromatography to obtain (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one.

[0013] Preferably, in step S1-1, the molar ratio of oxaloyl chloride, dimethylformamide, and 5-hexenoic acid is (1.5-2.0):(0.01-0.02):(1.0-1.3); the dichloromethane solution containing 5-hexenoic acid is obtained by uniformly mixing 5-hexenoic acid and dichloromethane in a mass ratio of (1.0-1.3):(1.5-2).

[0014] Preferably, in steps S1-2, the molar ratio of sodium hydride to (R)-4-isopropyloxazolidine-2-one is (1.3-1.5):(1.1-1.2); the mass ratio of sodium hydride to dry tetrahydrofuran is (1.3-1.5):(25-30); the dry tetrahydrofuran solution containing (R)-4-isopropyloxazolidine-2-one is obtained by uniformly mixing (R)-4-isopropyloxazolidine-2-one and dry tetrahydrofuran in a mass ratio of (1.1-1.2):(5-6), and the dry tetrahydrofuran solution containing crude acyl chloride solution is obtained by uniformly mixing crude acyl chloride solution and dry tetrahydrofuran in a mass ratio of (1.0-1.1):(5-6).

[0015] Preferably, step S2 includes the following specific steps:

[0016] Under argon protection and at -78 to -80°C, (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one was dissolved in dry tetrahydrofuran, and then sodium hexamethyldisilamide was slowly added at a rate of 20 to 25 ml / h. After stirring for 1 to 1.5 hours, iodomethane was added dropwise. The mixture was then stirred at -78 to -80°C for 2 to 2.5 hours, and then the temperature was raised to -60 to -50°C for 3 to 5 hours. The mixture was then quenched, separated, extracted, washed, dried, and concentrated. Finally, it was purified by silica gel column chromatography to obtain (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one.

[0017] Preferably, in step S2, the molar ratio of (R)-3-(5-hexenoyl)-4-isopropyloxazolidine to sodium hexamethyldisilamide is (1.0-1.1):(1.5-1.8), the molar ratio of sodium hexamethyldisilamide to iodomethane is (1.5-1.8):(5-6), and the mass ratio of (R)-3-(5-hexenoyl)-4-isopropyloxazolidine to dry tetrahydrofuran is (1.0-1.1):(10-11).

[0018] A (S)-5-methylundecene, wherein the (S)-5-methylundecene is synthesized using (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one as a starting material, wherein the (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one is the aforementioned (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one.

[0019] A method for synthesizing (S)-5-methylundecene, wherein the (S)-5-methylundecene is the (S)-5-methylundecene according to claim 4; the method for synthesizing (S)-5-methylundecene includes the following steps:

[0020] 1) (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one was reduced with LiAlH4 to obtain (R)-2-methyl-5-hexen-1-ol;

[0021] 2) (R)-2-methyl-5-hexen-1-ol was activated by reaction with TsCl, and then (S)-5-methylundecene was prepared by coupling with pentylmagnesium bromide under the catalysis of Li2CuCl4.

[0022] The (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one is the above-mentioned (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one.

[0023] Preferably, step 1) specifically includes the following steps:

[0024] Under argon protection and at 0℃ to -5℃, LiAlH4 was dissolved in dry tetrahydrofuran, and then slowly added dropwise to a dry tetrahydrofuran solution containing (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one at a rate of 30-35 ml / h. The temperature was then raised to 25-30℃ and stirred for 12-16 hours. The solution was then quenched, diluted, filtered, dried, and concentrated. Finally, it was purified by silica gel column chromatography to obtain (R)-2-methyl-5-hexen-1-ol.

[0025] Preferably, step 2) specifically includes the following steps:

[0026] 2-1) Under argon protection, p-toluenesulfonyl chloride was slowly added to a dry dichloromethane solution containing (R)-2-methyl-5-hexen-1-ol and triethylamine; then, the mixture was stirred at room temperature for 18 hours; then, the mixture was quenched, separated, extracted, washed, dried and concentrated to obtain crude p-toluenesulfonate, which was a colorless oil.

[0027] 2-2) Under argon protection and at -20℃ to -25℃, Li2CuCl4 was added to a dry tetrahydrofuran solution of crude p-toluenesulfonate, followed by slow addition of pentylmagnesium bromide. The mixture was then heated to room temperature and stirred overnight. The solution was then quenched, separated, extracted, washed, dried and concentrated, and purified by silica gel column chromatography to obtain (S)-5-methylundecene.

[0028] Preferably, in step 1), the molar ratio of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidine-2-one to LiAlH4 is (1.0-1.1):(3.5-3.8), and the dry tetrahydrofuran solution containing (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidine-2-one is obtained by uniformly mixing (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidine-2-one with dry tetrahydrofuran at a mass ratio of (1.0-1.1):(5-5.5), and the mass ratio of LiAlH4 to dry tetrahydrofuran is (3.5-3.8):(30-33).

[0029] Preferably, in step 2-1), the dry dichloromethane solution containing (R)-2-methyl-5-hexen-1-ol and triethylamine is obtained by uniformly mixing (R)-2-methyl-5-hexen-1-ol, triethylamine and dry dichloromethane in a molar ratio of (1.0-1.1):(1.75-2.0):(30-33), and the molar ratio of triethylamine to p-toluenesulfonyl chloride is (1.75-2.0):(2.0-2.3).

[0030] Preferably, in step 2-2), the molar ratio of crude p-toluenesulfonate, Li₂CuCl₄, and pentyl magnesium bromide is (1.0–1.1):(0.1–0.12):(3.0–3.6). The dried tetrahydrofuran solution of crude p-toluenesulfonate is obtained by uniformly mixing crude p-toluenesulfonate with dried tetrahydrofuran at a mass ratio of (1.0–1.1):(10–11). The Li₂CuCl₄ and hexyl magnesium bromide used in this application are existing reagents. The specification of Li₂CuCl₄ is (0.1 M, solution in THF), and the specification of hexyl magnesium bromide is (1.0 M, in THF).

[0031] A 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene, wherein the 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene is prepared using (S)-5-methylundecene as a raw material, wherein the (S)-5-methylundecene is the aforementioned (S)-5-methylundecene.

[0032] A method for synthesizing 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene, wherein the 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene is the aforementioned 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene; the method for synthesizing 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene includes the following steps:

[0033] A. (S)-5-methylundecene is subjected to a hydroboration oxidation reaction to synthesize (S)-5-methylundecene, and then (S)-5-methylundecene is subjected to an iodination reaction to synthesize the chiral intermediate (S)-1-iodo-5-methylundecene; wherein the (S)-5-methylundecene is the above-mentioned (S)-5-methylundecene.

[0034] B. Using (R)-2-methyl-5-hexen-1-ol, an iodination reaction was carried out to synthesize (R)-6-iodo-5-methyl-1-hexene. Then, (R)-6-iodo-5-methyl-1-hexene was reacted with p-Me(C6H4)SO2Na to synthesize (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene. Subsequently, (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene was alkylated with the chiral intermediate (S)-1-iodo-5-methylundecane to synthesize 1-(((5R,11S)-5,11-dimethylheptadecen-1-yl)-6-sulfonyl)-4-methylbenzene.

[0035] Preferably, step A) specifically includes the following steps:

[0036] Under argon protection, 9-boronbicyclo[3.3.1]nonene was slowly added to a dry tetrahydrofuran solution of (S)-5-methylundecene; after stirring at room temperature for 12–16 h, the temperature was lowered to 0–5 °C, and then sodium hydroxide solution was added and stirred for 30 min; after cooling to –20 °C, hydrogen peroxide solution was slowly added; then, the mixture was stirred at room temperature for 3 h, quenched, separated, extracted, washed, dried and concentrated, and purified by silica gel column chromatography to obtain (S)-5-methylundecene.

[0037] Under argon protection, (S)-5-methylundecyl alcohol, triphenylphosphine and imidazole were added to dry tetrahydrofuran and stirred until homogeneous. Then, a dry tetrahydrofuran solution of iodine was slowly added. After stirring for 3 to 5 hours, the mixture was quenched, separated, extracted, washed, dried and concentrated. After purification by silica gel column chromatography, (S)-1-iodo-5-methylundecylane was obtained.

[0038] Preferably, in step A), the molar ratio of (S)-5-methylundecene, 9-boronbicyclo[3.3.1]nonene, and sodium hydroxide is (1.0-1.1):(3.0-3.5):(6-7); the dry tetrahydrofuran solution of (S)-5-methylundecene is obtained by uniformly mixing (S)-5-methylundecene and the dry tetrahydrofuran solution in a mass ratio of (1.0-1.1):(15-17), the molar ratio of sodium hydroxide to hydrogen peroxide is (6-7):(18-21), the molar concentration of the sodium hydroxide solution is 3-3.5M, and the mass percentage of the hydrogen peroxide solution is 30%-35%.

[0039] The molar ratio of (S)-5-methylundecyl alcohol, triphenylphosphine, and imidazole is (1.0–1.1):(1.2–1.5):(2–3), the molar ratio of iodine to imidazole is (1.2–1.5):(2–3), and the mass ratio of (S)-5-methylundecyl alcohol to dry tetrahydrofuran is (1.0–1.1):(11–15).

[0040] Preferably, step B) specifically includes the following steps: under argon protection, (R)-2-methyl-5-hexen-1-ol, triphenylphosphine and imidazole are added to dry tetrahydrofuran and stirred until homogeneous. A dry tetrahydrofuran solution of iodine is slowly added. After stirring for 3 to 5 hours, the mixture is quenched, separated, extracted, washed, dried and concentrated. After purification by silica gel column chromatography, (R)-6-iodo-5-methyl-1-hexene is obtained.

[0041] Under argon protection, sodium p-toluenesulfinate, polyethylene glycol-400 (PEG-400), and dimethyl sulfoxide (DMSO) were mixed and stirred until homogeneous. (R)-6-iodo-5-methyl-1-hexene was then slowly added. The mixture was then heated to 80–85 °C and stirred for 2–3 hours. After cooling to room temperature, the mixture was quenched, separated, extracted, washed, dried, and concentrated. After purification by silica gel column chromatography, (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene was obtained.

[0042] Under argon protection and at -78 to -80°C, (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene was dissolved in dry tetrahydrofuran, and n-butyllithium (n-BuLi) was slowly added. The mixture was stirred at -78°C for 30 minutes, then heated to -35 to -30°C and stirred for 30 to 40 minutes. The mixture was then cooled to -78 to -80°C, and a mixed solution of hexamethylphosphoramide (HMPA), dry tetrahydrofuran, and (S)-1-iodo-5-methylundecane was slowly added. The mixture was then heated to room temperature and stirred overnight. The mixture was then quenched, separated, extracted, washed, dried, and concentrated. After purification by silica gel column chromatography, 1-(((5R,11S)-5,11-dimethylheptadecen-1-yl)-6-sulfonyl)-4-methylbenzene was obtained.

[0043] Preferably, in step B), the molar ratio of (R)-2-methyl-5-hexen-1-ol, triphenylphosphine, and imidazole is (1.0–1.1):(1.2–1.5):(2–3), the molar ratio of elemental iodine to imidazole is (1.2–1.5):(2–3), and the mass ratio of (R)-2-methyl-5-hexen-1-ol to dry tetrahydrofuran is (1.0–1.1):(11–15); (R)-6-iodo-5-methyl-1-hexene, sodium p-toluenesulfinate, polyethylene glycol-400, and The molar ratio of dimethyl sulfoxide (DMSO) is (1.0–1.1):(1.4–1.6):(17–20):(8–10); the molar ratio of (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene, n-butyllithium (n-BuLi), (S)-1-iodo-5-methylundecane, methylphosphoramide (HMPA), and dry tetrahydrofuran is (1.0–1.1):(1.5–1.8):(1.2–1.5):(4.8–6):(15–18).

[0044] A (5R,11S)-5,11-dimethylheptadecane, the structural formula of which is shown in Formula 1:

[0045]

[0046] The (5R,11S)-5,11-dimethylheptadecane is prepared using 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene; the 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene is the aforementioned 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene; and the (5R,11S)-5,11-dimethylheptadecane is a component of the sex pheromone of the western hemlock inchworm.

[0047] A method for preparing (5R,11S)-5,11-dimethylheptadecane, wherein the (5R,11S)-5,11-dimethylheptadecane is the aforementioned (5R,11S)-5,11-dimethylheptadecane; the method for preparing (5R,11S)-5,11-dimethylheptadecane includes the following steps:

[0048] (1) Remove the sulfonyl group from 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene by treatment with activated Mg / MeOH;

[0049] (2) (5R,11S)-5,11-dimethylheptadecane was synthesized by reduction with Pd / C catalyst.

[0050] Preferably, step (1) specifically includes the following steps:

[0051] Under argon protection, magnesium powder was dissolved in dry tetrahydrofuran, and then MeMgBr was added. After stirring at room temperature for 15-20 minutes, a dry methanol solution containing 1-(((5R,11S)-5,11-dimethylheptadec-1-yl)-6-sulfonyl)-4-methylbenzene was slowly added. Then, the mixture was stirred at 50-55°C for 4-6 hours. Subsequently, the mixture was quenched, separated, extracted, washed, dried, and concentrated to obtain the crude product (5S,11S)-5,11-dimethylheptadec-1-ene.

[0052] Preferably, in step (1), the mass ratio of 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene to magnesium powder is (1.0~1.1):(1.2~1.5), the mass ratio of magnesium powder to dry tetrahydrofuran is (1.2~1.5):(10~15), and the molar ratio of MeMgBr to magnesium powder is (0.02~0.03):(1 The dry methanol solution containing 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene is obtained by mixing 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene and MeOH in a mass ratio of (1.0-1.1):(30-35).

[0053] Preferably, step (2) specifically includes the following steps:

[0054] Under hydrogen protection, a methanol solution of the crude (5S,11S)-5,11-dimethylheptadec-1-ene was added to a methanol suspension containing palladium on carbon, which served as the Pd / C catalyst. The mixture was stirred at 25–30 °C for 12–15 hours and then concentrated under vacuum. After purification by silica gel column chromatography, (5R,11S)-5,11-dimethylheptadecane was obtained.

[0055] Preferably, in step (2), the mass ratio of 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene to palladium on carbon is (1.0-1.1):(0.2-0.3); the methanol suspension of palladium on carbon is obtained by uniformly mixing palladium on carbon and methanol in a mass ratio of (0.2-0.3):(8-10).

[0056] A (S)-7-methylheptadecane, the structural formula of which is shown in Formula 2:

[0057] The (S)-7-methylheptadecane is prepared using (S)-5-methylundecyl alcohol as a raw material; the (S)-5-methylundecyl alcohol is the aforementioned (S)-5-methylundecyl alcohol; and the (S)-7-methylheptadecane is another component of the sex pheromone of the western hemlock inchworm.

[0058] A method for preparing (S)-7-methylheptadecane, wherein the (S)-7-methylheptadecane is the aforementioned (S)-7-methylheptadecane; the method for preparing (S)-7-methylheptadecane includes the following steps:

[0059] a) Activate (S)-5-methylundecyl alcohol by reacting it with TsCl;

[0060] b) Coupling with hexyl magnesium bromide to synthesize (S)-7-methylheptadecane.

[0061] Preferably, step a) specifically includes the following steps:

[0062] Under argon protection, p-toluenesulfonyl chloride was slowly added to a dichloromethane solution containing (S)-5-methylheptadecyl alcohol and triethylamine, and stirred at room temperature for 18–20 hours. Then, the mixture was quenched, separated, extracted, washed, dried and concentrated, and purified by silica gel column chromatography to obtain the p-toluenesulfonate product.

[0063] Preferably, in step a), the molar ratio of triethylamine to p-toluenesulfonyl chloride is (1.75–2.0):(2.0–2.3); and the dichloromethane solution containing (S)-5-methylheptadecyl alcohol and triethylamine is obtained by uniformly mixing (S)-5-methylheptadecyl alcohol, triethylamine and dichloromethane, wherein the molar ratio of (S)-5-methylheptadecyl alcohol to triethylamine is (1.0–1.1):(1.75–2.0), and the mass ratio of (S)-5-methylheptadecyl alcohol to dichloromethane is (1.0–1.1):(30–33);

[0064] Preferably, step b) specifically includes the following steps:

[0065] Under argon protection and at -20°C, Li₂CuCl₄ and hexyl magnesium bromide were added to a dry tetrahydrofuran solution of p-toluenesulfonate; then, the temperature was gradually raised to room temperature and stirred overnight at room temperature; then, the mixture was quenched, separated, extracted, washed, dried and concentrated, and purified by silica gel column chromatography to obtain (S)-7-methylheptadecane.

[0066] Preferably, in step b), the molar ratio of p-toluenesulfonate to Li₂CuCl₄ is (1.0–1.1):(0.1–0.12), the molar ratio of Li₂CuCl₄ to hexyl magnesium bromide is (0.1–0.12):(3.0–3.6), and the dry tetrahydrofuran solution of p-toluenesulfonate is obtained by mixing p-toluenesulfonate and dry tetrahydrofuran at a mass ratio of (1.0–1.1):(10–11). The Li₂CuCl₄ and hexyl magnesium bromide used in this application are both existing reagents. The specification of Li₂CuCl₄ is (0.1M, solution in THF), and the specification of hexyl magnesium bromide is (1.0M, in THF).

[0067] A method for synthesizing (5R,11S)-5,11-dimethylheptadecane (i.e., component 1 of the sex pheromone of the western hemlock looper) includes the following steps:

[0068] First, (S)-5-methylundecene was synthesized from (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one.

[0069] Then, using (S)-5-methylundecene as a raw material, 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene was synthesized;

[0070] Finally, using 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene as a raw material, (5R,11S)-5,11-dimethylheptadecane (i.e. component 1 of the sex pheromone of the western hemlock looper) was synthesized.

[0071] A method for synthesizing (S)-7-methylheptadecane (i.e., component 2 of the sex pheromone of the western hemlock looper) includes the following steps:

[0072] First, (S)-5-methylundecene was synthesized from (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one.

[0073] Then, (S)-5-methylundecene was used as a raw material to synthesize (S)-5-methylundecene;

[0074] Finally, (S)-7-methylheptadecane (i.e., component 2 of the sex pheromone of the western hemlock looper) was synthesized using (S)-5-methylundecyl alcohol as a raw material.

[0075] Compared with the prior art, the beneficial technical effects of this application are as follows:

[0076] (1) This application provides a new method for synthesizing (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidine-2-one. The (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidine-2-one synthesized in this application has an optical purity greater than 99% and a synthesis yield of up to 68%.

[0077] This application utilizes (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one to synthesize component 1 of the sex pheromone of the western hemlock looper (i.e., (5R,11S)-5,11-dimethylheptadecane), with a total yield of up to 18%, and the optical purity of the synthesized (5R,11S)-5,11-dimethylheptadecane is greater than 99%.

[0078] This application utilizes (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one to synthesize component 2 (i.e. (S)-7-methylheptadecane) of the sex pheromone of the western hemlock looper, with a total yield of up to 30%, and the synthesized (5R,11S)-5,11-dimethylheptadecane has an optical purity greater than 99%. Attached Figure Description

[0079] Figure 1 The (R)-2-methylhex-5-en-1-yl(R)-3,3,3-trifluoro-2-methoxy-2-phenylpropionate was obtained by proton NMR spectroscopy. 1 H NMR spectrum. Detailed Implementation

[0080] Example 1:

[0081] The synthetic method for (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) is illustrated by the following reaction route:

[0082]

[0083] The synthetic method for (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) specifically includes the following steps:

[0084] S1. Under argon protection, 1.72 g (15 mmol) of 5-hexenoic acid was dissolved in 20 ml of dry dichloromethane (DCM) to obtain a dichloromethane solution containing 5-hexenoic acid. The structural formula of 5-hexenoic acid is shown in Formula 4. The temperature was then adjusted to 0 °C. Oxaloyl chloride (2.86 g, 22.5 mmol) and 0.1 ml of dimethylformamide (DMF) were then slowly added, followed by stirring at 0 °C for 2 hours. The solvent was then removed by vacuum concentration to obtain a pale yellow crude acyl chloride product. Under argon protection and at 0 °C, sodium hydride (0.9 g, 22.5 mmol) was dissolved in 20 ml of dry tetrahydrofuran. Sodium hydride was a commercially available reagent with the specification: NaH. 60% was dispersed in mineral oil; then, a dry tetrahydrofuran solution containing (R)-4-isopropyloxazolidin-2-one was slowly added to obtain a reaction solution, wherein the structural formula of (R)-4-isopropyloxazolidin-2-one is shown in Formula 5. The dry tetrahydrofuran solution of (R)-4-isopropyloxazolidin-2-one was obtained by mixing (R)-4-isopropyloxazolidin-2-one (3.46 g, 19.5 mmol) and 20 ml of dry tetrahydrofuran. Then, the reaction solution was heated to 25 °C and stirred for 2 hours; then cooled to 0 °C, and the slightly yellow crude acyl chloride product was dissolved in 10 ml of tetrahydrofuran to obtain a dry tetrahydrofuran solution containing the crude acyl chloride product. The dry tetrahydrofuran solution containing the crude acyl chloride product was slowly added dropwise. The mixture was added to the reaction solution and stirred at room temperature for 4 hours. Then, the reaction was quenched with saturated ammonium chloride aqueous solution (20 ml) to obtain the reaction material. After the reaction material separated into layers, an aqueous phase was obtained. The liquid-liquid separation process was completed. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 50 ml. Then, the three organic phase samples were mixed and washed with brine (50 ml). The mixture was then dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one (as shown in Formula 6), which was a light yellow oil (3.04 g, yield 90%).

[0085] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one. The results are as follows: [α] D 25 = -67.66 (c 1.80, CHCl3); 1H NMR(400MHz,Chloroform-d)δ5.85–5.75(m,1H),5.12–4.94(m,2H),4.45–4.41(m 1H),4.30–4.17(m,2H),3.03–2.84(m,2H),2.41–2.33(m,1H),2.13(q,J=7 .2Hz,2H),1.83–1.71(m,2H),0.91(d,J=7.0Hz,3H),0.87(d,J=6.9Hz,3H); 13 C NMR(101MHz, CDCl3)δ173.20,154.14,137.91,115.36,63.42,58.45,34.90,33.11,28.46,23.63,18.04,14.73; HRMS(ESI,m / z):calculated for[M+Na] + C 12 H 19 NO3Na 248.1257,found:248.1240.

[0086] S2. Under argon protection and at -78°C, (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one (3.38 g, 15 mmol) was dissolved in dry tetrahydrofuran (40 ml). The structural formula of (R)-3-(5-hexenoyl)-4-isopropyloxazolidin-2-one is shown in Formula 6. Then, sodium hexamethyldisilamide (NaHMDS, 11.25 ml, 2.0 M in THF, 22.5 mmol) was slowly added at a rate of 20 ml / h. Sodium hexamethyldisilamide was a readily available reagent. After stirring for 1 hour, iodomethane (MeI, 4.67 ml, 75 mmol) was added dropwise. Then, the mixture was heated at -78°C. The mixture was stirred for 2 hours at ℃, then heated to -60℃ and reacted for 3 hours. The reaction was then quenched with saturated ammonium chloride aqueous solution (30 ml) to obtain the reaction material. After the reaction material separated into layers, an aqueous phase was obtained. The aqueous phase was extracted three times with ethyl acetate, with 50 ml of ethyl acetate used in each extraction. The mixed organic phase was washed with brine (50 ml), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:8) to obtain (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7), which was a colorless oil (2.73 g, yield 76%).

[0087] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one. The results are as follows:

[0088] [α] D 25 = -91.08 (c 0.55, CHCl3); 1 H NMR(400MHz,Chloroform-d)δ5.83–5.73(m,1H),5.03–4.89(m,2H),4.46–4.42(m,1H),4.28–4.18(m,2H),3.80–3.71(m,1H),2.38–2.31 (m,1H),2.06(q,J=7.1Hz,2H),1.90–1.81(m,1H),1.52–1.45(m,1H),1.21(d,J=6.9Hz,3H),0.91(d,J=7.0Hz,3H),0.87(d,J=6.9Hz,3H); 13 C NMR (101MHz, CDCl3) δ177.17,153.78,138.30,114.99,63.37,58.57,37.34,32.30,31.68,28.60,18.08,18.06,14.85; HRMS (ESI, m / z): calculated for [M+Na] + C 13 H 21 NO3Na 262.1414, found: 262.1417.

[0089] Example 2:

[0090] The preparation method of (S)-5-methylundecene (as shown in Formula 10) is illustrated by the following reaction route:

[0091]

[0092] The preparation method of (S)-5-methylundecene (as shown in Formula 10) specifically includes the following steps:

[0093] 1) Under argon protection and at 0°C, LiAlH4 (1.50 g, 38.75 mmol) was dissolved in 15 ml of dry tetrahydrofuran to obtain a mixture; then (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidine-2-one (2.65 g, 11.07 mmol) (as shown in Formula 7) was dissolved in 15 ml of dry tetrahydrofuran and then slowly added dropwise to the mixture at a rate of 30 ml / h for 20 minutes; then... The mixture was heated to 25°C and stirred for 12 hours. Then, 20 ml of saturated ammonium chloride aqueous solution was slowly added to quench the precipitate, and the mixture was diluted with ethyl acetate. The precipitate was then removed by vacuum filtration. The filtrate was dried over anhydrous sodium sulfate and then filtered to obtain the filtrate. The filtrate was concentrated under reduced pressure. The residue after concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain (R)-2-methyl-5-hexen-1-ol (as shown in Formula 8), which was a colorless oil (1.09 g, yield 86%, ≥99% ee).

[0094] Optical purity of (R)-2-methyl-5-hexen-1-ol-derived mosel ester was determined by NMR;

[0095] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (R)-2-methyl-5-hexen-1-ol. The results are as follows:

[0096] [α] D 25 = +7.17(c 0.61, CHCl3); 1 H NMR(400MHz,Chloroform-d)δ5.86–5.76(m,1H),4.98(dd,J=27.7,13.6Hz,2H),3.53–3.41(m,2H),2.18– 2.00(m,2H),1.70–1.59(m,1H),1.56–1.47(m,1H),1.41(s,1H),1.25–1.16(m,1H),0.93(d,J=6.7Hz,3H); 13 C NMR(101MHz, CDCl3)δ139.03,114.54,68.31,35.35,32.43,31.31,16.57; HRMS(ESI,m / z):calculated for[M+K] + C7H 14 OK 153.0676, found:153.0662.

[0097] 2) Under argon protection, a dry dichloromethane solution containing (R)-2-methyl-5-hexen-1-ol (as shown in Formula 8) and triethylamine is slowly added to a dry dichloromethane solution of p-toluenesulfonyl chloride. The dry dichloromethane solution of p-toluenesulfonyl chloride is obtained by thoroughly mixing p-toluenesulfonyl chloride (1.90 g, 10.0 mmol) with 20 mL of dry chloromethane. The dry dichloromethane solution containing (R)-2-methyl-5-hexen-1-ol (as shown in Formula 8) and triethylamine is obtained by mixing (R)-2-methyl-5-hexen-1-ol (0.57 g, 5.0 mmol) and triethylamine (1.24 mL, 8.75 mmol) with 20 mL of dry dichloromethane. The mixture of 1 mmol) and 10 mL of dry dichloromethane was homogeneous; then, the mixture was stirred at room temperature for 18 hours; then, the mixture was quenched with saturated sodium bicarbonate aqueous solution (20 mL), and the reaction mixture separated into layers to obtain an aqueous phase. The liquid-liquid separation process was then completed, and the mixture was extracted three times with dichloromethane to obtain three organic phase samples, with 30 mL of dichloromethane used in each extraction. After mixing the three organic phase samples, the mixed organic phase sample was washed with brine (30 mL), dried with anhydrous sodium sulfate, and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain crude p-toluenesulfonate product, which was a colorless oil.

[0098] Under argon protection and at -20°C, Li₂CuCl₄ (5.0 mL, 0.5 mmol) was added to a dry tetrahydrofuran solution of the crude p-toluenesulfonate product. The dry tetrahydrofuran solution of the crude p-toluenesulfonate product was obtained by uniformly mixing the crude p-toluenesulfonate product (5.0 mmol, 1.0 equivalent) with 10 mL of dry tetrahydrofuran (10 mL). The Li₂CuCl₄ used in this application is an existing reagent with a specification of (0.1 M, solution in THF). Then, pentyl magnesium bromide (15.0 mL, 15.0 mmol, as shown in Formula 9) was slowly added. The pentyl magnesium bromide used in this application is an existing reagent with a specification of (1.0 M, solution in THF). The mixture was heated to room temperature and stirred overnight (THF). The reaction was then quenched with saturated ammonium chloride aqueous solution (30 mL). After the reaction was complete, the reactants separated into layers to obtain an aqueous phase. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. Each extraction used 40 mL of ethyl acetate. The organic phase samples were mixed and washed with brine (40 mL), dried with anhydrous sodium sulfate, and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (petroleum ether) to obtain (S)-5-methylundecene (as shown in Formula 10, 0.70 g, yield 83%), which was a colorless oil.

[0099] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-5-methylundecene. The results are as follows:

[0100] [α] D 25 = -1.22(c 0.65, CHCl3); 1 H NMR(400MHz,Chloroform-d)δ5.87–5.77(m,1H),5.05–4.90(m,2H),2.13–1.98(m ,2H),1.44–1.36(m,2H),1.31–1.24(m,9H),1.21–1.07(m,2H),0.90–0.85(m,6H); 13 C NMR (101MHz, CDCl3) δ139.65,114.06,37.11,36.40,32.44,32.10,31.55,29.83,27.13,22.85,19.68,14.28; HRMS (ESI, m / z): calculated for [M+Na] + C 12 H 24 Na 191.1770, found: 191.1786.

[0101] In this application, (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) contains two chiral centers, making it impossible to directly determine its enantiomeric excess (ee) value. To determine the optical purity of this compound, this application is based on Mosel esterification derivatization of (R)-2-methyl-5-hexen-1-ol (as shown in Formula 8) followed by optical testing. (R)-2-methyl-5-hexen-1-ol is derived from (R)-4-isopropyl-3- The optical purity of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) is demonstrated by optical testing following the reduction conversion of (R)-2-methyl-5-hexen-1-ol and subsequent Mosel esterification derivatization. The reaction pathway for the Mosel esterification derivatization of (R)-2-methyl-5-hexen-1-ol is shown below:

[0102]

[0103] The reaction of (R)-2-methyl-5-hexen-1-ol by Mosel esterification comprises the following steps: Under argon protection and at 0°C, 4-dimethylaminopyridine (DMAP, 12.2 mg, 0.1 mmol, 1.0 equiv.) and triethylamine (50.6 mg, 0.5 mmol, 5.0 equiv.) were dissolved in 4 mL of dichloromethane, followed by the dropwise addition of (R)-2-methyl-5-hexen-1-ol (as shown in Formula 8, 11.4 mg, 0.1 mmol, 1.0 equiv.), and stirring for 10 minutes. Then, (S)-(-)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride (50.6 mg) was added dropwise. ,0.2 mmol, 2.0 equiv.), and then stirred at room temperature for 12 hours; then quenched with water (3 mL), and then extracted three times with dichloromethane to obtain three organic phase samples, with 10 mL of dichloromethane used in each extraction; after mixing the three organic phase samples, the mixed organic phase samples were washed with brine (20 mL), then dried with anhydrous sodium sulfate, and concentrated under reduced pressure; the residue after reduced pressure concentration was purified by preparative chromatography to obtain (R)-2-methylhex-5-en-1-yl(R)-3,3,3-trifluoro-2-methoxy-2-phenylpropionate (as shown in Formula 23, 21.8 mg, yield 66%), as a colorless oil.

[0104] (R)-2-methylhex-5-en-1-yl(R)-3,3,3-trifluoro-2-methoxy-2-phenylpropionate (as shown in Formula 23) was subjected to 1H NMR spectroscopy, yielding... Figure 1 shown 1 H NMR spectrum. From 1 As can be seen from the H NMR spectrum: 1 HNMR(400MHz,Chloroform-d)δ7.53–7.51(m,2H),7.41–7.40(m,3H),5.80–5.70(m,1H),5.02–4.94(m,2H),4.24(dd,J=10.7,5.6Hz,1H),4. 10(dd,J=10.7,6.5Hz,1H),3.55(s,3H),2.14–1.99(m,2H),1.92–1.84(m,1H),1.51–1.42(m,1H),1.31–1.22(m,1H),0.93(d,J=6.8Hz,3H). HRMS(ESI,m / z):calculated for[M+H] + C 17 H 22 F3O3331.1510,found:331.1516.

[0105] from Figure 1 As can be seen from this, (R)-2-methylhex-5-en-1-yl(R)-3,3,3-trifluoro-2-methoxy-2-phenylpropionate (as shown in Formula 23) 1 The chemical shift at 3.551 in the 1H NMR spectrum is methoxy, because 1 The 1H NMR spectrum shows only a single peak at chemical shift 3.551, with no other single peaks observed at this position. This proves that the compound is a single isomer without other diastereomers. Simultaneously, the chiral methyl group at chemical shift 0.93 also shows only a doublet at this position, with no other doublets observed. This spectrum demonstrates that the optical purity of (R)-2-methylhexane-5-en-1-yl(R)-3,3,3-trifluoro-2-methoxy-2-phenylpropionate (as shown in Formula 23) is greater than 99%. Since (R)-2-methylhexane-5-en-1-yl(R)-3,3,3-trifluoro 2-Methoxy-2-phenylpropionate is derived from (R)-2-methyl-5-hexen-1-ol (as shown in Formula 23) via esterification, thus indicating that the optical purity of (R)-2-methyl-5-hexen-1-ol is greater than 99%. Since (R)-2-methyl-5-hexen-1-ol is derived from (R)-4-isopropyl-3-((R)-2-methyl-5-hexenyl)oxazolidin-2-one via reduction, this also indicates that the optical purity of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenyl)oxazolidin-2-one (as shown in Formula 7) is greater than 99%.

[0106] Example 3:

[0107] The synthetic method for 1-(((5R,11S)-5,11-dimethylheptadecen-1-yl)-6-sulfonyl)-4-methylbenzene (as shown in Formula 15) is illustrated by the following reaction route:

[0108]

[0109]

[0110] The method for synthesizing 1-(((5R,11S)-5,11-dimethylheptadecen-1-yl)-6-sulfonyl)-4-methylbenzene (as shown in Formula 15) specifically includes the following steps:

[0111] A. Under argon protection, 9-boronbicyclo[3.3.1]nonene (9-BBN, 22.8 mL, 0.5 M in THF, 11.4 mmol) was slowly added to a dry tetrahydrofuran solution of (S)-5-methylundecene (as shown in Formula 10), wherein the 9-boronbicyclo[3.3.1]nonene is a readily available chemical reagent, and the dry tetrahydrofuran solution of (S)-5-methylundecene (as shown in Formula 10) was obtained by mixing (S)-5-methylundecene (0.64 g, 3.8 mmol) with 10 mL of dry tetrahydrofuran; then, the mixture was stirred at room temperature for 12 hours, then cooled to 0°C, and then sodium hydroxide solution (7.6 mL, 3 M, 22.8 mmol) was added, and the mixture was stirred for 30 minutes; Then, the temperature was lowered to -20℃, and hydrogen peroxide solution (7.6 mL, 30 wt%) was slowly added; then, after stirring at room temperature for 3 hours, the reaction was quenched with saturated ammonium chloride aqueous solution (15 mL) to obtain the reaction material. After the reaction material separated into layers, an aqueous phase was obtained, and the separation process was completed. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 50 mL. After mixing the three organic phases, the mixed organic phase was washed with brine (50 mL) and dried with anhydrous sodium sulfate, and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:10) to obtain (S)-5-methylundecyl alcohol (as shown in Formula 11, 0.57 g, yield 80%), which is a colorless oil.

[0112] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-5-methylundecyl alcohol. The results are as follows:

[0113] [α] D 25 = -1.41 (c 0.85, CHCl3); 1 H NMR (400MHz, Chloroform-d) δ3.64(t,J=6.6Hz,2H),1.62–1.48(m,2H),1.43–1.19(m,14H),1.16–1.04(m,2H),0.94–0.79(m,6H); 13 CNMR(101MHz, CDCl3)δ63.25,37.16,36.98,33.30,32.89,32.09,29.82,27.17,23.36,22.84,19.77,14.26; HRMS(ESI,m / z):calculated for[M+Na] + C 12 H 26 ONa 209.1876,found:209.1882.

[0114] B) Under argon protection, (S)-5-methylundecyl alcohol (as shown in Formula 11, 0.37 g, 2.0 mmol), triphenylphosphine (0.63 g, 2.4 mmol), and imidazole (0.30 g, 4.4 mmol) were placed in 5 mL of dry tetrahydrofuran and stirred until homogeneous. A dry tetrahydrofuran solution of iodine was slowly added, which was obtained by thoroughly mixing elemental iodine (0.61 g, 2.4 mmol) with 5 mL of dry tetrahydrofuran. The mixture was then stirred at 25 °C for 3 hours, followed by stirring with 5 wt% Na₂S₂O₃. The reaction was quenched with aqueous solution to obtain the reactants. After the reactants separated into layers, an aqueous phase was obtained. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 30 mL. The organic phase samples were mixed and washed with Na2S2O3 aqueous solution (5 wt%), water and brine, and dried with anhydrous sodium sulfate. The mixture was then concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (petroleum ether) to obtain (S)-1-iodo-5-methylundecane (as shown in Formula 12, 0.52 g, 88% yield), which is a light yellow oil.

[0115] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-1-iodo-5-methylundecane. The results are as follows:

[0116] [α] D 25 = +0.88 (c 0.90, CHCl3); 1 H NMR(500MHz,Chloroform-d)δ3.19(t,J=7.0Hz,2H),1.85–1.76(m,2H),1.45–1.34(m,3 H),1.32–1.24(m,10H),1.15–1.07(m,2H),0.88(t,J=6.9Hz,3H),0.85(d,J=6.6Hz,3H); 13 C NMR(126MHz, CDCl3)δ37.11,36.01,34.02,32.74,32.09,29.81,28.16,27.15,22.84,19.77,14.27,7.52; HRMS(ESI,m / z):calculated for[M+H] + C 12 H 26 I 297.1074, found:297.1063.

[0117] Under argon protection, (R)-2-methyl-5-hexen-1-ol (as shown in Formula 8, 0.29 g, 2.5 mmol), triphenylphosphine (0.79 g, 3.0 mmol), and imidazole (0.37 g, 5.5 mmol) were placed in 8 mL of dry tetrahydrofuran and stirred until homogeneous. A dry tetrahydrofuran solution of iodine was slowly added, which was obtained by thoroughly mixing iodine (0.76 g, 3.0 mmol) with 8 mL of dry tetrahydrofuran. After stirring for 3 hours, the reaction was quenched with a 5 wt% Na₂S₂O₃ aqueous solution. The reactants were obtained and separated into aqueous phases. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 40 mL. The three organic phases were mixed and washed with Na2S2O3 aqueous solution (5 wt%), water and brine, and dried with anhydrous sodium sulfate. The mixture was then concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (petroleum ether) to obtain (R)-6-iodo-5-methyl-1-hexene (as shown in Formula 13, 0.45 g, yield 80%), which was a light yellow oil.

[0118] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (R)-6-iodo-5-methyl-1-hexene. The results are as follows:

[0119] [α] D 25 = -2.90 (c 0.83, CHCl3); 1 H NMR(500MHz,Chloroform-d)δ5.83–5.75(m,1H),5.05–5.01(m,1H),4.99–4.95(m,1H),3.24(dd,J=9.6,4.4Hz,1 H),3.17(dd,J=9.7,5.7Hz,1H),2.09–2.04(m,2H),1.52–1.45(m,2H),1.35–1.27(m,1H),0.99(d,J=6.4Hz,3H); 13 C NMR(126MHz, CDCl3)δ138.40,114.97,35.70,34.17,31.24,20.60,17.75; HRMS(ESI,m / z):calculated for[M+H] + C 17 H 14 I 225.0135, found:225.0145.

[0120] Under argon protection, sodium p-toluenesulfinate (0.25 g, 1.4 mmol), polyethylene glycol-400 (PEG-400, 3 mL), and dimethyl sulfoxide (DMSO) (1.5 mL) were mixed and stirred until homogeneous. Then, (R)-6-iodo-5-methyl-1-hexene (as shown in Formula 13, 0.22 g, 1.0 mmol) was slowly added. The mixture was then heated to 80 °C and stirred for 2 hours. After cooling to room temperature, the reaction was quenched with a 10 wt% sodium chloride solution (10 mL) to obtain the reaction mixture. After the reaction mixture separated into layers, water was obtained. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 40 mL. The three organic phase samples were mixed, washed with water and brine, dried with anhydrous sodium sulfate, and then concentrated under vacuum. The residue after vacuum concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:8) to obtain (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene (as shown in Formula 14, 0.18 g, yield 70%), which was a colorless oil.

[0121] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene. The results are as follows:

[0122] [α] D 25 = -3.06 (c 0.95, CHCl3); 1 H NMR(500MHz,Chloroform-d)δ7.78(d,J=8.2Hz,2H),7.35(d,J=8.0Hz,2H),5.75–5.66(m,1H),4.99–4.89(m,2H),3.07(dd,J=14.2,4.7Hz,1H) ,2.91(dd,J=14.2,7.7Hz,1H),2.45(s,3H),2.15–2.05(m,1H),2.04–1. 92(m,2H),1.56–1.49(m,1H),1.37–1.29(m,1H),1.07(d,J=6.7Hz,3H); 13 C NMR(126MHz, CDCl3)δ144.63,137.95,137.36,130.02,128.04,115.15,62.75,35.93,30.76,28.29,21.76,19.87; HRMS(ESI,m / z):calculated for[M+H] + C 14 H 21 O2S253.1257, found:253.1259.

[0123] Under argon protection and at -78°C, (R)-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene (as shown in Formula 14, 0.15 g, 0.6 mmol) was dissolved in 10 mL of dry tetrahydrofuran, and n-butyllithium (n-BuLi, 2.4 M, 0.38 mL, 0.9 mmol) was slowly added; then, the mixture was stirred at -78°C for 30 minutes, followed by heating to -35°C and stirring for 30 minutes; then, the mixture was cooled to -78°C, and a mixed solution of hexamethylphosphoramide (HMPA) (0.42 mL), dry tetrahydrofuran (1 mL), and (S)-1-iodo-5-methylundecane (as shown in Formula 12, 0.21 g, 0.72 mmol) was slowly added; then, the mixture was heated... The mixture was cooled to room temperature and stirred overnight. Then, 1M hydrochloric acid (6 mL) was added to quench the reaction mixture, and the aqueous phase was obtained after separation. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 20 mL. The three organic phase samples were mixed and washed with saturated sodium bicarbonate solution and brine. The mixture was then dried with anhydrous sodium sulfate and concentrated under vacuum. The residue after vacuum concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:10) to obtain 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene (as shown in Formula 15, 0.19 g, yield 75%), which was a colorless oil.

[0124] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on 1-(((5R,11S)-5,11-dimethylheptadecen-1-yl)-6-sulfonyl)-4-methylbenzene. The results are as follows:

[0125] [α] D 25 = -0.38 (c 1.04, CHCl3); H NMR(500MHz,Chloroform-d)δ7.75(d,J=8.1Hz,2H),7.34(d,J=8.0Hz,2H),5 .80–5.62(m,1H),5.01–4.89(m,2H),2.91–2.85(m,1H),2.45(s,3H),2.23–2 .10(m,1H),2.04–1.81(m,3H),1.66–1.61(m,1H),1.40–1.35(m,1H),1.33–1 .11(m,17H),1.04–1.00(m,3H),0.88(t,J=6.9Hz,3H),0.79(d,J=6.5Hz,3H); 13C NMR(126MHz, CDCl3)δ144.39,137.91(138.50),136.54(136.86),129.86(129.83),128.7 3(128.70),115.18(114.97),68.30(69.70),37.16(37.13),36.69(36.72),35.18,32.73( 32.78),32.27,32.09(31.99),31.59,31.48(31.06),29.81,29.49(29.19),27.16(27.04 ),25.14,22.84(23.92),21.74,19.74(18.09),14.85,14.27; HRMS(ESI,m / z):calculated for[M+H] + C 26 H 45 O2S 421.3135,found:421.3117.

[0126] Example 4:

[0127] The synthetic method for (5R,11S)-5,11-dimethylheptadecane (i.e., component 1 of the sex pheromone of the western hemlock looper, its structural formula is shown in Formula 1) is as follows: The synthetic route is shown in the following reaction formula:

[0128]

[0129] The synthesis method of the sex pheromone (5R,11S)-5,11-dimethylheptadecane from the western hemlock inchworm specifically includes the following steps:

[0130] (1) Under argon protection, magnesium powder (0.13 g, 5.4 mmol) was dissolved in dry tetrahydrofuran (1.0 mL), and two drops of MeMgBr (3.0 M) were added. After stirring at room temperature for 15 minutes, a dry methanol solution of 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene (as shown in Formula 15) was slowly added, wherein the dry methanol solution of 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene was prepared by adding 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl) The mixture of 4-methylbenzene (0.15 g, 0.35 mmol) and 5.0 mL of dry methanol was homogenized and stirred at 50 °C for 4 hours. The methanol was then removed by concentration, and the reaction was quenched by adding 2 mL of cold 1 M hydrochloric acid solution to obtain the reaction material. After the reaction material separated into layers, an aqueous phase was obtained. The liquid-liquid separation process was completed. The aqueous phase was extracted three times with diethyl ether to obtain three organic phase samples. The amount of diethyl ether used in each extraction was 10 mL. The three organic phase samples were mixed, and the mixed organic phase was washed with saturated sodium bicarbonate solution and brine, dried with anhydrous sodium sulfate, and concentrated under vacuum to obtain crude (5S,11S)-5,11-dimethylheptadec-1-ene.

[0131] Under hydrogen protection, the crude product of (5S,11S)-5,11-dimethylheptadec-1-ene was dissolved in 3 mL of methanol to obtain a methanol solution of the crude product. This solution was then added to a methanol suspension containing palladium on carbon (30 mg) and 2 mL of methanol. The mixture was stirred at 25 °C for 12 hours, followed by vacuum concentration. The residue after vacuum concentration was purified by silica gel column chromatography (petroleum ether) to obtain (5R,11S)-5,11-dimethylheptadecane (63.9 mg, yield 68%), which was a colorless oil. The specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry of (5R,11S)-5,11-dimethylheptadecane were determined, and the results are as follows:

[0132] [α] D 25 = -0.93(c 0.63, CHCl3); 1 H NMR(500MHz,Chloroform-d)δ1.41–1.33(m,2H),1.31–1.21(m,22H),1.14–1.03(m,4H),0.91–0.87(m,6H),0.86–0.81(m,6H); 13CNMR (126MHz, CDCl3) δ37.27,36.94,32.92,32.90,32.13,30.54,30.20,29.90,29.86 ,29.51,27.28,27.21,23.21,22.86,19.89,14.33,14.28; HRMS(ESI,m / z):calculated for[M+K] + C 19 H 40 K307.2762, found: 307.2751.

[0133] Example 5:

[0134] The synthetic method of (S)-7-methylheptadecane (i.e., component 2 of the sex pheromone of the western hemlock looper, the structural formula of which is shown in Formula 2) is as follows: The synthetic route is shown in the following reaction formula:

[0135]

[0136] The synthesis method of the sex pheromone (S)-7-methylheptadecane from the western hemlock inchworm includes the following steps:

[0137] Under argon protection, a dichloromethane solution of p-toluenesulfonyl chloride was slowly added to a dichloromethane solution containing (S)-5-methylheptadecyl alcohol (as shown in Formula 11) and triethylamine. The p-toluenesulfonyl chloride dichloromethane solution was obtained by thoroughly mixing p-toluenesulfonyl chloride (0.19 g, 1.0 mmol) and dichloromethane (2 mL). The dichloromethane solution containing (S)-5-methylheptadecyl alcohol (as shown in Formula 11) and triethylamine was obtained by thoroughly mixing (S)-5-methylheptadecyl alcohol (0.57 g, 0.5 mmol) and triethylamine (0.12 mL, 0.88 mmol) with a dichloromethane solution (2 mL). The mixture was stirred at room temperature for 18 hours after homogenization with 4 mL of saturated sodium bicarbonate solution to obtain the reaction material. After the reaction material separated into layers, an aqueous phase was obtained. The aqueous phase was extracted three times with dichloromethane to obtain three organic phase samples. The amount of dichloromethane used in each extraction was 15 mL. The three organic phase samples were mixed, and the mixed organic phase was washed with brine (20 mL) and dried with anhydrous sodium sulfate. The mixture was then concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain the p-toluenesulfonate product, which was a colorless oil.

[0138] Under argon protection and at -20°C, Li₂CuCl₄ (0.5 mL, 0.05 mmol) and hexyl magnesium bromide (1.5 mL, 1.5 mmol, as shown in Formula 16) were added to a dry tetrahydrofuran solution of p-toluenesulfonate. In this application, hexyl magnesium bromide is an existing reagent. The dry tetrahydrofuran solution of p-toluenesulfonate was obtained by thoroughly mixing p-toluenesulfonate (0.5 mmol, 1.0 equivalent) and dry tetrahydrofuran (2 mL). The mixture was then heated to room temperature and stirred overnight, followed by the addition of saturated... The reaction was quenched with ammonium chloride solution (5 mL) to obtain the reactants. After the reactants separated into layers, an aqueous phase was obtained. The separation process was completed. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 30 mL. The three organic phase samples were mixed, washed with brine (30 mL), dried with anhydrous sodium sulfate, and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (petroleum ether) to obtain (S)-7-methylheptadecane (98 mg, yield 77%), which was a colorless oil.

[0139] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-7-methylheptadecane. The results are as follows: [α] D 25 =-1.76(c 0.87, CHCl3); H NMR (400MHz, Chloroform-d) δ1.38–1.03(m,28H),1.09–1.04(m,1H),0.90–0.82(m,9H); 13 C NMR(101MHz, CDCl3)δ37.27,32.92,32.13,32.10,30.21,29.90,29.87,29.83,29.53,27.25,27.22,22.86,19.88,14.28; HRMS(ESI,m / z):calculated for[M+K] + C 18 H 38 K 293.2605, found:293.2601.

[0140] Example 6:

[0141] The synthetic method for (S)-2,5-dimethylheptadecane (i.e., component 3 of the sex pheromone of the western hemlock looper, its structural formula is shown in Formula 3) is as follows:

[0142]

[0143] The method for synthesizing (S)-2,5-dimethylheptadecane specifically includes the following steps:

[0144] Under argon protection, tetradecanoic acid (as shown in Formula 17, 0.91 g, 4 mmol) was dissolved in dry dichloromethane (DCM, 6 ml), and the temperature was adjusted to 0 °C. Then, oxalyl chloride (0.76 g, 6 mmol) and 0.1 ml methylformamide (DMF) were slowly added, and the mixture was stirred at 0 °C for 2 hours. The solvent was then removed under reduced pressure to obtain a pale yellow crude product, acyl chloride.

[0145] Under argon protection and at 0°C, sodium hydride (NaH 60% mineral oil, 0.15 g, 3.3 mmol) was dissolved in dry tetrahydrofuran (6 ml). Then, a dry tetrahydrofuran solution of (S)-4-isopropyloxazolidine-2-one (as shown in Formula 5) was slowly added, the mixture was heated to 25°C and stirred for 2 hours. The mixture was then cooled to 0°C, and a dry tetrahydrofuran solution of the crude product acyl chloride was slowly added. The mixture was then stirred at room temperature for 4 hours, and the reaction was quenched with a saturated ammonium chloride aqueous solution (10 ml) to obtain the reaction mixture. The dry tetrahydrofuran solution of (S)-4-isopropyloxazolidine-2-one was obtained by uniformly mixing (S)-4-isopropyloxazolidine-2-one (0.67 g, 5.2 mmol) and dry tetrahydrofuran (6 ml). The dried tetrahydrofuran solution of the crude acyl chloride was obtained by mixing the pale yellow crude acyl chloride with 10 ml of dried tetrahydrofuran. After the reaction materials were separated into layers, an aqueous phase was obtained. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 30 ml. The three organic phase samples were mixed, and the mixed organic phase was washed with brine (30 ml) and dried with anhydrous sodium sulfate. The mixture was then concentrated under reduced pressure. The residue after concentration under reduced pressure was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain (S)-4-isopropyl-3-tetradecanoyloxazolidin-2-one (as shown in Formula 19), which was a pale yellow oil (1.15 g, yield 85%).

[0146] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-4-isopropyl-3-tetradecanoyloxazolidin-2-one. The results are as follows:

[0147] [α] D 25 = +56.03 (c 3.02, CHCl3); 1H NMR(500MHz,Chloroform-d)δ4.44–4.41(m,1H),4.25(t,J=8.7Hz,1H),4.19(dd,J=9.1,3.0Hz,1H),3.00–2.94(m,1H), 2.87–2.81(m,1H),2.41–2.32(m,1H),1.69–1.59(m,2H),1.35–1.24(m,20H),0.90(d,J=7.1Hz,3H),0.88–0.86(m,6H); 13 C NMR (126MHz, CDCl3) δ173.56,154.20,63.42,58.50,35.65,32.04,29.80,29.77,29.73,29.61 ,29.50,29.48,29.26,28.51,24.60,22.81,18.10,14.78,14.24; HRMS(ESI,m / z):calculated for[M+K] + C 20 H 37 O3NK 378.2405,found:378.2405.

[0148] Under argon protection and at -78°C, (S)-4-isopropyl-3-tetradecanoyloxazolidin-2-one (as shown in Formula 19, 1.02 g, 3 mmol) was dissolved in dry tetrahydrofuran (8 ml); then, sodium hexamethyldisilamide (2.25 ml, 4.5 mmol) was slowly added, and after stirring for 1 hour, iodomethane (0.93 ml, 15 mmol) was added dropwise, wherein sodium hexamethyldisilamide is a readily available reagent (2.0 M, in THF); then, the mixture was stirred at -78°C for 2 hours, and then heated to -60°C and stirred for 3 hours; finally, the mixture was dissolved in a saturated ammonium chloride aqueous solution (1... The reaction was quenched with 0 ml to obtain the reaction material; after the reaction material was separated into layers, an aqueous phase was obtained, and the separation process was completed. The aqueous phase was extracted with ethyl acetate three times to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 30 ml. The three organic phase samples were mixed, and the mixed organic phase was washed with brine (30 ml) and dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:8) to obtain (S)-4-isopropyl-3-((S)-2-methyltetradecanoyl)oxazolidin-2-one (20), which was a colorless oil (0.83 g, yield 78%).

[0149] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-4-isopropyl-3-((S)-2-methyltetradecanoyl)oxazolidin-2-one. The results are as follows:

[0150] [α] D 25 = +60.61 (c 1.96CHCl3); 1 H NMR(500MHz,Chloroform-d)δ4.46–4.43(m,1H),4.25(t,J=8.7Hz,1H),4.20(dd,J=9.1,2.9Hz,1H),3.75–3.68(m,1H),2.38–2.32 (m,1H),1.74–1.66(m,1H),1.38–1.32(m,1H),1.30–1.23(m,20H),1.19(d,J=6.9Hz,3H),0.91(d,J=7.0Hz,3H),0.89–0.86(m,6H); 13 C NMR (126MHz, CDCl3) δ177.46,153.80,63.32,58.57,37.86,33.26,32.06,29.81,29.81,29.78,29 .73,29.65,29.50,28.57,27.45,22.82,18.08,17.99,14.82,14.25; HRMS(ESI,m / z):calculated for[M+Na] + C 21 H 39 O3NNa378.2822,found:378.2813;

[0151] Under argon protection and at 0°C, LiAlH4 (0.24 g, 6.3 mmol) was dissolved in dry tetrahydrofuran (3 ml), and then a dry tetrahydrofuran solution of (S)-4-isopropyl-3-((S)-2-methyltetradecanoyl)oxazolidine-2-one (as shown in Formula 20) was slowly added dropwise over 20 minutes. The dry tetrahydrofuran solution of (S)-4-isopropyl-3-((S)-2-methyltetradecanoyl)oxazolidine-2-one was prepared by dissolving (S)-4-isopropyl-3-((S)-2-methyltetradecanoyl)oxazolidine-2-one (0.64 g, 1.8 ml) in argon gas at 0°C. The mixture of mol) and dry tetrahydrofuran (5 ml) was homogeneous; then the temperature was raised to 25 °C and stirred for 12 hours, and then saturated ammonium chloride aqueous solution (10 ml) was slowly added to quench the reaction, and the reaction material was obtained. The reaction material was then diluted with ethyl acetate; the precipitate was filtered off, the filtrate was dried with anhydrous sodium sulfate and then filtered again to obtain the filtrate, which was concentrated under reduced pressure; the residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain (S)-2-methyltetradecanoic acid (as shown in Formula 21), which is a colorless oil (0.35 g, yield 81%, ≥99% ee);

[0152] The optical purity of (S)-2-methyltetradecaneol was determined by NMR spectroscopy of the mosel ester derived from (S)-2-methyltetradecaneol. Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry of (S)-2-methyltetradecaneol were also determined, and the results are as follows:

[0153] [α] D 25 = -10.60 (c 1.10, CHCl3); 1 H NMR(500MHz,Chloroform-d)δ3.51(dd,J=10.5,5.8Hz,1H),3.42(dd,J=10.5,6.6Hz,1H),1.64–1.57(m,1H ),1.39–1.35(m,2H),1.31–1.26(s,20H),1.13–1.07(m,1H),0.91(d,J=6.7Hz,3H),0.88(t,J=7.0Hz,3H); 13 CNMR(126MHz, CDCl3)δ68.58,35.92,33.30,32.07,30.10,29.83,29.81,29.80,29.51,27.13,22.84,16.73,14.26; HRMS(ESI,m / z):calculated for[M+Na] + C 15 H 32ONa 251.2345,found:251.2364.

[0154] Under argon protection, a dry dichloromethane solution containing (S)-2-methyltetradecyl alcohol (as shown in Formula 21) and triethylamine was slowly added to a dry dichloromethane solution of p-toluenesulfonyl chloride. The dry dichloromethane solution of p-toluenesulfonyl chloride was obtained by uniformly mixing p-toluenesulfonyl chloride (0.30 g, 1.6 mmol) and dry dichloromethane (4 mL). The dry dichloromethane solution containing (S)-2-methyltetradecyl alcohol (as shown in Formula 21) and triethylamine was obtained by mixing (S)-2-methyltetradecyl alcohol (0.18 g, 0.8 mmol) and triethylamine (0.2 mL, 1.4 mmol) with dry dichloromethane. The mixture was prepared by uniformly mixing 5 mL of dichloromethane and stirring at room temperature for 18 hours. The reaction was then quenched with 5 mL of saturated sodium bicarbonate solution to obtain the reactants. After separation, an aqueous phase was obtained. The aqueous phase was extracted three times with dichloromethane to obtain three organic phase samples, with 20 mL of dichloromethane used in each extraction. The three organic phase samples were mixed, washed with 20 mL of brine, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (ethyl acetate / petroleum ether = 1:5) to obtain p-toluenesulfonate. The crude p-toluenesulfonate product is a colorless oil. Under argon protection and at -20°C, Li₂CuCl₄ (0.8 mL, 0.08 mmol) was added to a dry tetrahydrofuran solution of the crude p-toluenesulfonate product. The dry tetrahydrofuran solution of the crude p-toluenesulfonate product was obtained by thoroughly mixing the crude p-toluenesulfonate product (0.8 mmol, 1.0 equivalent) with 2 mL of dry tetrahydrofuran. Li₂CuCl₄ was a commercially available reagent. Then, isobutylmagnesium bromide (4.8 mL, 2.4 mmol, as shown in Formula 22) was slowly added. Isobutylmagnesium bromide is an existing reagent with a specification of 0.5 M. The mixture was then heated to room temperature and stirred overnight. The reaction was then quenched with a saturated ammonium chloride aqueous solution (5 mL) to obtain the reaction material. After the reaction material separated into layers, an aqueous phase was obtained. The liquid-liquid separation process was completed. The aqueous phase was extracted three times with ethyl acetate to obtain three organic phase samples. The amount of ethyl acetate used in each extraction was 20 mL. The three organic phase samples were mixed, and the mixed organic phase was washed with brine (20 mL), dried with anhydrous sodium sulfate, and concentrated under reduced pressure. The residue after reduced pressure concentration was purified by silica gel column chromatography (petroleum ether) to obtain (S)-2,5-dimethylheptadecane (as shown in Formula 3, 0.15 g, yield 72%), which was a colorless oil.

[0155] Specific rotation, 1H NMR, 1C NMR, and high-resolution mass spectrometry were performed on (S)-2,5-dimethylheptadecane. The results are as follows:

[0156] [α] D 25 = -0.77 (c 1.04, CHCl3); 1 H NMR(400MHz,Chloroform-d)δ1.51–1.43(m,1H),1.34–1.23(m,23H),1.18–1.05(m,4H),0.90–0.83(m,12H); 13 C NMR (101MHz, CDCl3) δ37.27,36.55,34.93,33.18,32.10,30.21,29.90,29.87,29.83, 29.53,28.50,27.26,22.99,22.86,22.76,19.92,14.28; HRMS(ESI,m / z):calculated for[M+K] + C 19 H 32 NO3307.2762, found: 307.2758.

[0157] Example 7:

[0158] A method for synthesizing (5R,11S)-5,11-dimethylheptadecane (i.e., component 1 of the sex pheromone of the western hemlock looper, the structural formula of which is shown in Formula 1) includes the following steps:

[0159] First, using (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) as a starting material, (S)-5-methylundecene (as shown in Formula 10) was synthesized; wherein, the synthesis method of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) is consistent with the synthesis method of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one described in Example 1; and the preparation method of (S)-5-methylundecene is consistent with the synthesis method of (S)-5-methylundecene described in Example 2.

[0160] Then, using (S)-5-methylundecene (as shown in Formula 10) as a raw material, 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene (as shown in Formula 15) was synthesized; wherein, the synthesis method of 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene is consistent with the synthesis method of 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene described in Example 3;

[0161] Finally, using 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene (as shown in Formula 15) as a raw material, (5R,11S)-5,11-dimethylheptadecane (i.e., component 1 of the sex pheromone of the western hemlock looper, as shown in Formula 1) was synthesized; wherein, the synthesis method of (5R,11S)-5,11-dimethylheptadecane is consistent with the synthesis method of (5R,11S)-5,11-dimethylheptadecane described in Example 4.

[0162] Example 8:

[0163] A method for synthesizing (S)-7-methylheptadecane (i.e., component 2 of the sex pheromone of the western hemlock looper, the structural formula of which is shown in Formula 2) includes the following steps:

[0164] First, using (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) as a starting material, (S)-5-methylundecene (as shown in Formula 10) was synthesized; wherein, the synthesis method of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one (as shown in Formula 7) is consistent with the synthesis method of (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one described in Example 1; and the preparation method of (S)-5-methylundecene is consistent with the synthesis method of (S)-5-methylundecene described in Example 2.

[0165] Then, using (S)-5-methylundecene (as shown in Formula 10) as a raw material, (S)-5-methylundecene (as shown in Formula 11) was synthesized; wherein, the method for synthesizing (S)-5-methylundecene is consistent with the method for synthesizing (S)-5-methylundecene in step A of Example 3;

[0166] Finally, using (S)-5-methylundecyl alcohol (as shown in Formula 11) as a raw material, (S)-7-methylheptadecane (i.e., component 2 of the sex pheromone of the western hemlock looper, as shown in Formula 2) was synthesized; wherein, the synthesis method of (S)-7-methylheptadecane is consistent with the synthesis method of (S)-7-methylheptadecane described in Example 5.

Claims

1. A 1-(((5) R ,11 S A method for synthesizing 5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene, characterized in that: Includes the following steps: A. ( S (S)-5-methylundecene undergoes a hydroboration oxidation reaction to synthesize (S)-5-methylundecyl alcohol, and then ( S )-5-methylundecyl alcohol undergoes an iodination reaction to synthesize a chiral intermediate ( S )-1-Iodo-5-methylundecane; B. Utilizing ( R )-2-methyl-5-hexen-1-ol was subjected to an iodination reaction to synthesize ( R )-6-iodo-5-methyl-1-hexene, then, ( R )-6-iodo-5-methyl-1-hexene and p -Me(C6H4)SO2Na reacts to synthesize ( R )-1-methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene, and then, ( R )-1-Methyl-4-((2-methyl-5-hexenyl)sulfonyl)benzene with chiral intermediate ( S 1-Iodo-5-methylundecane undergoes alkylation to synthesize 1-(((5) R ,11 S 5,11-Dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene; The method for synthesizing (S)-5-methylundecene includes the following steps: 1) (R)-4-isopropyl-3-((R)-2-methyl-5-hexenoyl)oxazolidin-2-one was reduced by LiAlH4 to obtain (R)-2-methyl-5-hexen-1-ol; 2) (R)-2-methyl-5-hexen-1-ol was activated by reaction with TsCl, and then coupled with pentylmagnesium bromide under the catalysis of Li2CuCl4 to prepare (S)-5-methylundecene.

2. A type of (5) R ,11 S A method for synthesizing 5,11-dimethylheptadecane, characterized in that: Including the following step: First, with ( R )-4-Isopropyl-3-(( R Using 2-methyl-5-hexenoyl)oxazolidin-2-one as a starting material, 1-(((5) is synthesized by the method described in claim 1. R ,11 S 5,11-Dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene; Finally, with 1-(((5) R ,11 S (5R,11S)-5,11-dimethylheptadecane was synthesized from 5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene, including the following steps: (1) Remove the sulfonyl group from 1-(((5R,11S)-5,11-dimethylheptadecene-1-yl)-6-sulfonyl)-4-methylbenzene by treatment with activated Mg / MeOH; (2) (5R,11S)-5,11-dimethylheptadecane was synthesized by reduction with Pd / C catalyst.

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