Synthesis of C2-symmetrical bis-β-amino alcohols from (R)-cysteine and their application in enantioselective catalysis

Six new sulfur-containing C-2-symmetrical bis-beta-primary and sec-amino-tert-alcohols have been synthesized from (R)-cysteine and applied successfully in the enantiocontrolled catalytic addition of diethylzinc to benzaldehyde. The resulting 1-phenyl-1-propanol could be obtained in good enantiomeric excess of up to 94%. Using the same chiral auxiliaries in the enantioselective borane reduction of acetophenone afforded l-phenyl-l-ethanol in enantiomeric excesses of up to 82%. (C) 1998 Elsevier Science Ltd. All rights reserved.