Desosamine 1 (Scheme 1) was chosen as the residue upon which we would build glycosylated small molecule libraries as a proof-of-concept demonstration of PGD. The main factors that influenced this choice were the ready availability of desosamine from erythromycin via hydrolysis, and the fact that amino sugars frequently contribute to binding when they are present on small molecules. A well-established sequence of reactions was used to form the starting material for PGD precursor preparation. Desosamine was converted to its pyrimidyl glycoside via a Mitsunobu reaction with mercaptopyrimidine, and then the C2 hydroxyl group was protected as its methyl carbonate to give compound 2 (49%, over two steps). Initially, three different alcohols were glycosylated with this donor: azido ethanol, m-bromobenzyl alcohol, and pbromobenzyl alcohol. After glycosylation, the carbonate was removed by solvolysis in a methanol water mixture. Yields for the twostep sequence are shown in Scheme 1.