The path of the conversion of 3,5,6-tri-O-benzoyl-1,2-O-isopropylidene-α-D-glucose into 4,5,6-tri-O-benzoyl-2,3-di-S-ethyl-2,3-dithio-D-allose diethyl dithioacetal

Abstract

The reaction whereby 4,5,6-tri-O-benzoyl-2,3-di-S-ethyl-2,3-dithio-D-allose diethyl dithioacetal can be obtained efficiently by direct ethanethiolysis of 3,5,6-tri-O-benzoyl-1,2-O-isopropylidene-α-D-glucose is shown to take place by way of 2-S-ethyl-2-thio-D-mannose intermediates. Migration of the 2-ethylthio-group to C-3 and of the 3-benzoyl substituent to C-4 follow, and an additional ethylthio-group is introduced at C-2.