Fluorocarbohydrates. Part XIV. Reaction of N-(2-chloro-1,1,2-trifluoroethyl)diethylamine with some O-isopropylidene sugars

Abstract

N-(2-Chloro-1,1,2-trifluoroethyl)diethylamine reacted at room temperature with 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose, 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose, and methyl 3,4-O-isopropylidene-β-L-arabinopyranoside to give the respective 3-, 6-, and 2-O-chlorofluoroacetates. Under alkaline conditions, these compounds were hydrolysed to the parent isopropylidene-sugar and sodium chlorofluoroacetate. The latter was characterised as the S-benzylthiouronium salt. The amine reacted similarly with 1,2-O-isopropylidene(±)-glycerol, giving 3-O-chlorofluoroacetyl-1,2-O-isopropylidene-(±)-glycerol. With 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose in dimethylformamide at 60° in the presence of anhydrous potassium fluoride, the amine gave a mixture from which was isolated 6-chloro-6-deoxy-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose, giving on acid hydrolysis crystalline 6-chloro-6-deoxy-α-D-galactose.