17- O-Acetyl testosterone, which has no susceptible hydroxyl or carboxyl group for glycosylation, was glycosylated with 2,3,4,6-tetra- O-acetyl- α- d-glucopyranosyl bromide in the presence of a mixed catalyst, Hg(CN) 2 and HgBr 2, in benzene–nitromethane. Reaction occurred on the α, β-unsaturated ketone on the six–membered A-ring to give six 3- O-glycosides, each bearing a cyano group at the 3- or 5-position of the aglycon, and a 3- O-glycoside bearing a CONH 2 group at the 3-position. Structural analyses of these products were carried out by various NMR ( 1H, 13C NMR, 1H– 1H and 1H– 13C COSY, HMBC, and DEPT), FABMS and X-ray analyses. The mechanisms of the formations of the products are discussed. It was determined that mercuric cyanide was essential as a catalyst for the progress of the cyanoglycosylation.