AN IMPROVED SYNTHETIC PREPARATION OF ANTI CONFORMATIONALLY CONSTRAINED ACYCLIC NUCLEOSIDES

Practical large-scale synthesis of anti conformationally constrained acyclic nucleosides has been attained from the coupling of lithiated 2,4-dimethoxy-5,6-dimethylpyrimidine with 1,3-bis(tert-butyldiphenylsilyloxy)-propan-2-one, followed by the sequential reactions of methylthiomethylation, ring cyclization, hydrolysis, and desilylation.