A common route to the synthesis of 1,3,4-oxadiazole-2-thione and 1,2,4-triazole-3-thiols derivatives of trioses and pentoses as models for acyclic C-nucleosides

The 5-(1,2-dihydroxy-ethyl)-3H-[1,3,4]oxadiazole-2-thione (12) and 1-(5-mercapto-4H[1,2,4]triazole-3-yl)-ethane-1,2-diol (13) derived from (+/-) glyceraldehyde (resembles trioses) have been synthesized from glycerol (1) via a common route. The synthesis of the optical active 5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3H-[1,3,4]oxadiazole-2-thione (17) and 5-(2,2- dimethyl[1,3]dioxolan-4-yl)-4H-[1,2,4]triazole-3-thiol (18) may be achieved by the same common route when the D-glyceraldehyde (3) was obtained by cleavage oxidation of 1,2: 5,6-Di-O-isopropylidene D-mannitol (15). Similar derivatives 23 and 24 of D-xylose (19) (resembles pentoses) may also be synthesized by the same common route from (tetrahydro-[1,3]dioxino[5,4d][1,3]dioxin-4-yl)-methanol (21). This common route provides a simple synthetic pathway to acyclic C-nucleosides and to less extent to cyclic C-nucleosides.