Hepta-O-acetyl-2-O-β-L-quinovopyranosyl-α-D-glucose (VI) and hepta-O-acetyl-2-O-α-L-quinovopyranosyl-β-D-glucose (VIII) were prepared by the coupling of 2, 3, 4-tri-O-acetyl-α-L-quinovopyranosyl bromide (IV) with 1, 3, 4, 6-tetra-O-acetyl-α-D-glucose (V) in the presence of mercuric cyanide and mercuric bromide in absolute acetonitrile.
Similarly, hepta-O-acetyl-2-O-α-L-quinovopyranosyl-α-D-galactose (X) and hepta-O-acetyl-2-O-β-L-quinovopyranosyl-α-D-galactose (XI) were prepared by the reaction of IV with 1, 3, 4, 6-tetra-O-acetyl-α-D-galactose (IX).
Removal of the protecting groups of VI, VIII, X and XI afforded the corresponding disaccharides. On treatment with hydrogen bromide, VI, VIII, X and XI gave the corresponding acetobromo derivatives.