Increased Felkin−Anh Selectivity Using AlMe₃in the Addition of Vinyllithiums to α-Chiral Aldehydes:  Do “Ate” Complexes Play Any Role?

Abstract

[reaction: see text] AlMe(3) dramatically increases the diastereoselectivity of addition of vinyllithiums to alpha-chiral aldehydes but decreases that of methyllithium. Our results are explained in terms of an addition of the free vinyllithium on the Me(3)Al-aldehyde complex.