Stereoselective Reductive Cross Aldol Reaction between Bromoaldehyde and Aldehyde Using Germanium(II) Chloride

摘要

The reaction of alpha-bromoaldehydes with aldehydes mediated by germanium(II) chloride as a reductant gave the cross-aldol products in syn-selectivity.A catalytic amount of Bu_4NBr significantly improved the yield and diastereoselectivity.Various types of bromoaldehydes and aldehydes including aromatic and aliphatic ones were applicable.An intramolecular version of this system also proceeded to give the cyclic cross-aldol derivative.