The synthesis of oxazaborolidines from amides derived from ephedrine and pseudoephedrine by treatment with BH3-THF is reported. The reaction affords chiral oxazaborolidines with nitrogen atom substituents of different steric requirements enlarging the potential of new oxazaborolidines prepared from readily available ephedrines. These may be useful in asymmetric synthesis.
Stereoselective synthesis of 1,2-amino alcohols by asymmetric borane reduction of α-oxoketoxime ethers
作者:Moriyasu Masui、Takayuki Shioiri
DOI:10.1016/s0040-4039(98)01019-3
日期:1998.7
Asymmetricreduction of α-oxoketoxime ethers with the reagents prepared in situ from trimethyl borate and chiral amino alcohols derived from either L-proline or α-pinene was investigated. Both cyclic and acyclic α-oxoketoxime ethers were reduced to afford the corresponding chiral 1,2-amino alcohols with high enantioselectivities.