Synthesis and separation of diastereoisomers of (R,S)-1-methyl-3-[3-(aryl)-1,2,4-oxadiazol-5-yl] ethyl 2,3-dideoxy-alfa-D-erythro-hex-2-enopyranosides

Abstract

: This work describes the syntheses of diastereoisomers of (R,S)-1-methyl-3-[3-(aryl)-1,2,4-oxadiazol-5-yl] ethyl 2,3-dideoxy- a -D-erythro-hex-2-enopyranosides. For synthesizing title compounds, first we carried out the Ferrier’s rearrangement involving tri-O-acetyl-D-glucal 1 and alcohols 2a–f using Montmorillonite K-10 as a catalyst. This reaction gave diastereoisomeric mixture of 3a-e and 4a–e . Basic hydrolysis of each pair of diastereoisomeric mixture furnished title compounds 5a–e and 6a–e , which were separated very carefully over a silica gel column yielding all diastereoisomers in the pure form. All compounds were obtained in good yield and characterized by spectral data ( 1 H and 13 C NMR, IR).