Study On Synthesis Of The Intermediates Of Sex Pheromone Of Boll Weevil And Oxidative Cyclisation Of Hydroxyl-terminatedamides To Cyclic Imides

(+)-Grandisol1is a sex pheromone of cotton boll weevil. It is used for pestmanagement as an insect sex attractants. Its excellent performance of cheaper,more efficient and environment-friendly has been attracting great attention.Due to there are few reports of (+)-Grandisol in China and the complicatedmoleculer structure, the production technology of (+)-Grandisol needs furtherimprovement. Therefore in this paper some synthetic methods of (+)-Grandisol areintroduced, compared, screened and optimized. And finally an applicable industrialprocess was established with important intermediate,6-methylhept-5-enenitrile.Taking5-chloropentanenitrile as starting materials, through bromination, Wittigreaction,6-methylhept-5-enenitrile is attained, which is then reacted with2-(2-bromoethoxy) tetrahydro-2H-pyran to acquire6-methyl-2-(2-(tetrahydro-2H-pyran-2-yloxy)ethyl)hept-5-enenitrile. The intermediate converted into cyclobutaneintermediate of sex pheromone of cotton boll weevil by the use of lithiumhexamethyldisilazide.In addition, the problems of pyridinium chlorochromate (PCC) oxidative primaryand second alcohols to carbonyl compounds contained in current synthesis of (+)-Grandisol are analyzed. PCC mediated oxidative cyclization of hydroxyl-terminatedamides is discovered in our paper. The optimum reaction conditions are found bystudy a arrange reaction of hydroxyl-terminated amides and PCC. A novel andeffiective method for synthesis of cyclic imides is provided by oxidative cyclizationof hydroxy-terminal amides with PCC.