Cyclic saligenyl phosphotriesters of 2′,3′-dideoxy-2′,3′-didehydrothymidine (d4T) — a new pro-nucleotide approach

The synthesis of a new pro-nucleotide approach for d4TMP 2 based on cycloSal-d4TMP 3a-d is described. Phosphotriesters 3 release d4TMP 2 selectively by a controlled, chemically induced tandem reaction. CycloSal-phosphotriesters 3 exhibited high biological activity against HIV-1/HIV-2 in CEM cells which was retained in CEM TK− cells.