ol0485417_si_001.pdf (5.35 MB)
Direct Organocatalytic Asymmetric Aldol Reactions of α-Amino Aldehydes: Expedient Syntheses of Highly Enantiomerically Enriched anti-β-Hydroxy-α-amino Acids
journal contribution
posted on 2004-09-30, 00:00 authored by Rajeswari Thayumanavan, Fujie Tanaka, Carlos F. BarbasA simple and efficient method for the synthesis of highly enantiomerically enriched β-hydroxy-α-amino acid derivatives has been developed.
Direct asymmetric aldol reactions of a glycine aldehyde (aminoacetaldehyde) derivative have been performed under organocatalysis using
l-proline or (S)-5-pyrrolidine-2-yl-1H-tetrazole. The reactions afforded anti-β-hydroxy-α-amino aldehydes in good yield with high diastereoselectivity
(dr up to >100:1) and high enantioselectivity (up to >99.5% ee), which were easily transformed into β-hydroxy-α-amino acid derivatives.