Monoesters of arylacetic acid, their production and use.

摘要

The invention provides optically active esters of arylacetic acid of the formula: wherein R<1> is hydrogen or optionally substituted C1-C2 alkyl or phenyl or when both taken together form C2-C6 alkylene, C2 or C4-C6 alkenylene, or a bicyclic-ring; R<2> is hydrogen or methyl; X is a single bond or CH2, C=O, N-R<4>, O, S, CHNHR<4>, CHCH3, CH-Ar, or CHOR<5> (provided that when X is single bond or CH2, C=O, N-R<4>, O, or S, R<1> and R<2> are not simultaneously hydrogen or methyl); R<3> is hydrogen, optionally substituted alkyl, or optionally substituted aralkyl; R<4> is hydrogen or an amino protecting group; R<5> is hydrogen or a hydroxy protecting group; and Ar is optionally substituted aryl. These esters may be prepared by the reaction of a sigma symmetric acid anhydride with an (R)- or (S)-arylacetic acid derivative in high optical purity, and are useful as intermediates for various optically active natural products and medicines.