Synthesis of 3-O-(α-D-glucopyranosyl)-1,2-di-O-stearoyl-L-glycerol, a ‘glucosyl diglyceride’

Abstract

3-O-(3,4-Di-O-benzyl-α-D-glucopyranosyl)-1,2-O-isopropylidene-L-glycerol was converted into 3-O-(α-D-glucopyranosyl)-1,2-di-O-stearoyl-L-glycerol, a ‘glucosyl diglyceride.’ 1,6-Anhydro-2,3,4-tri-O-benzyl-β-D-glucopyranose was converted by acetyl chloride and hydrogen chloride into 6-O-acetyl-2,3,4-tri-O-benzyl-D-glucopyranosyl chloride, which was condensed with 1,2-di-O-(but-2-enyl)-L-glycerol under conditions shown previously to give predominantly 1,2-cis-glycosidic linkages. The product was treated with potassium t-butoxide in dimethyl sulphoxide to give crystalline 3-O-(2,3,4-tri-O-benzyl-α-D-glucopyranosyl)-L-glycerol, which was also prepared from 3-O-(3,4-di-O-benzyl-α-D-glucopyranosyl)-1,2-O-isopropylidene-L-glycerol. 3-O-(2,3,4-Tri-O-benzyl-α-D-glucopyranosyl)-L-glycerol was converted into the ‘glucosyl diglyceride’ and also into 3-O-(2,3,4-tri-O-benzyl-α-D-glucopyranosyl)-1,2-di-O-stearoyl-L-glycerol, which should serve as an intermediate for the syntheses of a ‘glucuronosyl diglyceride,’ the ‘plant sulpholipid.’ and one of the phosphorylated ‘glucosyl diglycerides’ of Streptococci.