MODEL SYNTHESES OF THIAZOLIDINE NUCLEOSIDE ANALOGS

The syntheses of racemic thiazolidinyl thymine and cytosine derivative s 6a and 6b, and 10a and 10b, prototypes of a novel family of heterosu bstituted nucleosides, have been achieved from rhodanine (3) or thiazo lidine (7) by a short sequence of steps. The key reaction involved eff icient coupling of silylated thymine and cytosine to N-Boc-protected 4 - and 5-acetoxythiazolidines, 5 and 9, assisted by tert-butyldimethyls ilyl trifluoromethanesulfonate.