Abstract The syntheses of racemic thiazolidinyl thymine and cytosine derivatives 6a and 6b, and 10a and 10b, prototypes of a novel family of heterosubstituted nucleosides, have been achieved from rhodanine (3) or thiazolidine (7) by a short sequence of steps. The key reaction involved efficient coupling of silylated thymine and cytosine to N-Boc-protected 4- and 5-acetoxythiazolidines, 5 and 9, assisted by terr-butyldimethylsilyl trifluoromethanesulfonate.