Double-headed acyclo C-nucleoside analogues. Functionalized 1,2-bis-(1,2,4-triazol-3-yl)ethane-1,2-diol

Reaction of L-tartaric acid with thiocarbohydcrazide afforded (1R, 2S)-1,2-bis(4-amino-5-mercapto-1,2,4-triazol-3-yl)-ethane-1,2-diol (3). The functional groups in 3 allowed the construction of fused heterocycles on the 1,2,4-triazole rings, mainly of the 1,2,4-triazolo3,4-b]1,3,4]thiadiazine type as in 4, 5, 7, 10, 13 and 1,2,4-triazolo3,4-b]1,3,4]thiadiazole type as in 14.