Formation of cyclic sulfonium salts by Me3SiI-promoted intramolecular displacement of hydroxide or methoxide by sulfide. Ring contraction thiepane → thiolane
作者:Vanda Cere`、Salvatore Pollicino、Antonino Fava
DOI:10.1016/0040-4020(96)00229-3
日期:1996.4
methyl ethers). The outcome may be a cyclic sulfonium salt or an iodide arising from cleavage of a sulfonium intermediate. Cyclization is especially favored with secondary and tertiary alcohols or ethers, and with an aliphatic more than an aromatic sulfide function. A transannular version of the reaction results in the facile ring contraction of a 7- to a 5-membered cyclic sulfide.
适当定位的(1、2、1、1、4和1、5-)分子内硫化物会干扰碘代三甲基硅烷促进的碘的羟基取代,以及相关的醇脱保护步骤(甲基醚的区域选择性裂解)。结果可能是由于intermediate中间体的裂解而产生的环状an盐或碘化物。特别优选仲和叔醇或醚以及脂族而不是芳族硫化物官能团的环化。该反应的跨环形形式导致7元至5元环状硫化物的容易的环收缩。