Synthesis of 3-O-{6-O-[6-O-(α-D-galactopyranosyl)-α-D-galactopyranosyl]-β-D-galactopyranosyl}-1,2-di-O-stearoyl-L-glycerol, a ‘trigalactosyl diglyceride’

Abstract

2,3,4-Tri-O-benzyl-6-O-but-2-enyl-α-D-galactopyranosyl chloride was condensed with 3-O-[6-O-(2,3,4-tri-O-benzyl-α-D-galactopyranosyl)-2,3,4-tri-O-benzyl-β-D-galactopyranosyl]-1,2-O-isopropylidene-L-glycerol under conditions shown previously to give predominantly 1,2-cis-glycosides. The product was converted into the crystalline tris-p-nitrobenzoate of 3-O-{6-O[6-O-(2,3,4-tri-O-benzyl-α-D-galactopyranosyl)-2,3,4-tri-O-benzyl-α-D-galactopyranosyl]-2,3,4-tri-O-benzyl-β-D-galactopyranosyl}-L-glycerol which was further elaborated to afford the title compound.