Lithium aluminium hydride reduction of chiral benzoylformamides derived from chiral amino alcohols

Abstract

The reduction of benzoylformamides derived from various N- and O-substituted (S)-amino alcohols using lithium aluminium hydride was carried out. Diastereoisomeric excesses could be determined by chromatographic separation of the resulting diastereoisomeric mandelamides. In all cases, the (S,S)diastereoisomer was obtained as the major product (1–72% d.e.), and the degree of asymmetric induction depended largely on the N- and O-substituents of the amino alcohol moiety. A d.e. of up to 72% was obtained for the benzoylformamide (4) derived from N-methylvalinol.