Highly diastereoselective epimerization: stereodivergent synthesis of α-hydroxy-β-amino isopentanoic acid = 알파-히드록시-베타-아미노 이소펜탄오익 에시드의 입체선택적인 합성

Abstract

The high diastereoselectivity of the base-catalyzed epimerization of oxazolidin-2-ones 7 and 8 is shown to depend on the nature of the N-substituent (R group); when R = Bn, the 4,5-trans-product (4S,5R)-9 is formed, whereas when R = H the 4,5-cis-product (45,55)-10 is formed, both with >99:1 dr. The successful hydrolysis of the oxazolidin-2-one group in both cis- and trans-derivatives show this to be a stereodivergent route to enantiopure α-hydroxy-β-amino isopentanoic acids (2R,3S)-1 and (25,35)-2.