Protecting Group Manipulation on D-Glucosamine Propane-1,3-Diyl Dithioacetal

D-glucosamine propane-1,3-diyl dithioacetal is a versatile synthetic building block, especially when being incorporated with the Corey-Seebach method. Hence, exploring compatible protecting group patterns on this compound mainly for use with the Corey-Seebach method is a fundamental work. Various protecting group strategies were applied. Typically, N- protection of D- glucosamine propane- 1,3- diyl dithioacetal yielded N- phthaloyl, N-Boc, and N-Ac derivatives. On the N-Ac derivative, experiments differentiating 3,4- and 5,6- hydroxyls by basic stable protecting groups yielded useful intermediates. Selective protections of the 6- hydroxyl of the N-Ac derivative were also applied. The remaining secondary hydroxyls of the resulting N-Ac-6-O- acyl D- glucosamine propane-1,3- diyl dithioacetals could be methoxymethylated to tri-O-MOM derivatives or protected by a unique one- pot discriminating protection to form the N-acyl-6-O-acyl-3,4-O-methylene-5- O-methoxymethyl D-glucosamine propane-1,3-diyl dithioacetals as useful intermediates.