A Novel Approach for Stereochemical Analysis of 1-Carboxyethyl Sugar Ethers by NMR Spectroscopy

Article abstract of DOI:10.1021/ja00056a041

A general strategy for the stereochemical analysis of 1-carboxyethyl sugar ethers is introduced in which the chirality of the lactyl group is related to that of the sugar moiety in a conformationally rigid lactone derivative.With the aid of molecular modeling, the stereochemistry is determined through the use of NOE measurements.This procedure was evaluated using synthetic diastereomeric samples of (R)- and (S)-methyl 3-O-(1-carboxyethyl)-α-L-rhamnopyranoside, and it was successfully applied to the stereochemical analysis of N-acetylmuramic acid.The generality of this approach is illustrated here with a 4-O-substituted 1-carboxyethyl sugar ether.It was found that the lactyl group of 4-O-(1-carboxyethyl)-D-mannopyranose, which was obtained from the capsular polysaccharide of Rhodococcus equi serotype 3, has the (S)-configuration.