Olefinic stereoselection in the [2,3]-Wittig rearrangement of α,β-disubstituted allylic ethers forming trisubstituted olefins

Abstract

The E Z - selectivities in the [2,3]-Wittig rearrangements of secondary β-(methyl or silyl)allylic ethers are shown to depend critically on the nature of groups on the carbanion terminus, thereby permitting elucidation of the structural requirements for attaining high Z-selectivity.