A novel extension of the Stork–Jung vinylsilane Robinson annelation procedure for the introduction of the cyclohexene of guanacastepene
作者:Barry B Snider、Bo Shi
DOI:10.1016/s0040-4039(01)02026-3
日期:2001.12
has been developed in a model system to introduce the cyclohexene ring of guanacastepene. Cyclohexenone 16 is prepared by sequential methylation and alkylation with allylic iodide 15. One-pot epoxidation, protodesilylation and hydrolysis of the THP forms dione 19, which cyclizes with NaOMe to 24 in 57% overall yield. Reduction, Mitsunobu inversion, and selective oxidation of the primary alcohol forms
在模型系统中开发了一种新的脱嵌程序,以引入胍卡斯蒂芬的环己烯环。环己烯酮16是通过顺序甲基化和与烯丙基碘15烷基化制备的。THP的一锅环氧化,原去甲硅烷基化和水解形成二酮19,该二酮与NaOMe环化成24,收率为57%。伯醇的还原,Mitsunobu转化和选择性氧化形成模型29。苯基二甲基甲硅烷基烯丙基碘化物36比Stork使用的三甲基甲硅烷基烯丙基碘化物6更容易制造且更稳定。