Stereoselective synthesis of 1,2-amino alcohols by addition of organocuprate·BF3 complexes and organolithium reagents to an α-silyloxyaldimine derived from (S)-ethyl lactate

Article abstract of DOI:10.1016/0040-4020(96)00776-4

1,2-Amino alcohols were synthesized by addition of organocuprate·BF₃ 2 (R = n-Bu, n-octyl, Me, phenethyl, Ph), organocopper·BF₃ 3 (R = Me, n-Bu), and organolithiums (R = n-Bu, n-octyl, Me, phenethyl, Ph) to an α-silyloxyaldimine 1 derived from commercially available (S)-ethyl lactate. The reactions with organocuprate·BF₃ 2 and organocopper·BF₃ 3 led to the anti isomers almost exclusively (anti:syn = > 98: < 2 for R = n-Bu, n-octyl, Me, phenethyl and anti:syn = 95:5 for R = Ph, 52-93% isolated yields) and the syn isomers could be obtained with high stereoselectivities by using organolithiums (anti:syn = 10:90-20:80, 41-71% isolated yields).