The stereoselective synthesis of β-branched carboxylic acid derivatives was accomplished
by conjugate addition of mixed organoaluminum reagents to chiral α,β-unsaturated N-acyloxazolidinones. Mixed organoaluminum reagents were generated in situ by transmetalation
of Grignard or organolithium compounds with methylaluminum dichloride. Efficient
stereocontrol was achieved using different bicyclic glycosamine-derived oxazolidinones,
yielding alternatively (R)- or (S)-configured β-branched carboxylic acid derivatives.
stereoselective Michael additions - organoaluminum compounds - chiral carboxylic acids
- carbohydrates - auxiliaries
