Chelated [3,3]-rearrangements of difluoroallylic alcohols
摘要:
Whereas the lithium enolates of acetate and propionate esters of difluoroallylic alcohols fragment rapidly, even at -78 degrees C, methoxy-and benzyloxy-acetates form chelated enolates which undergo smooth [3,3]-rearrangement as their silyl ketene acetals. The latent ketone function can be revealed under mild conditions (MeOH, SOCl2) to afford very highly functionalised CF2 compounds. (C) 1997 Elsevier Science Ltd.