Enantioselective preparation of (2R,3R)-(+)- and (2S,3S)-(-)-2,3-epoxy-2-methylbutanoic acids and some derivatives

摘要

(2R,3R)-(+)- and (2S,3S)-(-)-2,3-epoxy-2-methylbutanoic acids (epoxyangelic acids) were prepared from (Z)-2-methyl-2-butenoic acid using the Sharpless asymmetric epoxidation method in combination with the use of(-)and (+)-menthol as chiral auxiliaries. Both substances, obtained in high enantiomeric excess, were characterized by spectroscopic and optical activity data. Their absolute configuration was determined by correlation with (R)-(+)-2-methyl-1,2-butanediol. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 15]