Specific features of phase transfer catalytic glycosylation of aromatic hydroxy acids

Reactions of peracetylated α-D-glucosaminyl chloride with isomeric hydroxybenzoic and 1-hydroxy-2-naphthoic acids in a solid phase transfer system of potassium carbonate-acetonitrile were studied. It was found that the nature of carboxylic acids, lipophilicity of the phase transfer catalyst, and reaction temperatures affected the reaction composition and product yields. The O-β-glycosyl esters of ortho-hydroxyaromatic acids were first found to form anomeric 1,2-cis derivatives in the presence of potassium carbonate. The structures of the synthesized compounds were confirmed by ¹H NMR spectroscopy. As was shown in vivo experiments, the analgesic activities of glycosyl esters of salicylic acid and peracetylated 2-carboxyphenylglucosaminide were comparable with that of aspirin.