Stereocontrolled synthesis of E-homoallylic sulfides with 1,4,5 related chiral centres using the [2,3] sigmatropic rearrangement of sulfonium ylides
作者:Richard C. Hartley、Ian C. Richards、Stuart Warren
DOI:10.1039/p19960000359
日期:——
An aldol condensation sets up the stereochemistry. Lactonisation with 1,2 arylsulfanyl migration followed by reduction and sulfur-assisted dehydration converts the aldols stereospecifically into allylic sulfides with 1,2 related chiral centres. Sulfonium salts are generated from the allylic sulfides at low temperature, and are deprotonated to give sulfonium ylides which undergo [2,3] sigmatropic rearrangement
具有1,4,5个相关手性中心的E-均烯丙基硫化物已经以立体控制的方式合成。醛醇缩合建立了立体化学。1,2,4-芳基硫烷基迁移后进行还原和硫辅助脱水的拉克斯顿化将羟醛立体定向转化为具有1,2相关手性中心的烯丙基硫化物。low盐是在低温下由烯丙基硫化物生成的,并被去质子化,以基离子形式进行[[2,3]σ重排,收率很高,从而得到E-具有1,4,5个相关手性中心的同质烯丙基硫化物。1,4相对立体化学是由立体特异性手性转移产生的,并且与烯丙基硫化物1,2的相对立体化学直接相关。还观察到高的4,5非对映选择性。提供了观察到的立体选择性的解释。