A SIMPLE ONE-POT SYNTHESIS OF 1-(S-TRIAZOLO[4,3-X]AZINYL-3)-SUBSTITUTED POLYOLS

Open-chain C-nucleosides, 1-(s-triazolo[4,3-x]azinyl-3)polyols 13-18 w ere prepared by one-pot synthesis from hydrazinoazines 20a,c and vario us D-aldoses 1-6. No protective groups were required for these transfo rmations. 1-(s-Triazolo[4,3-b]pyridazinyl-3)-D-xylo-tetritol (15a) was isolated and characterised in the form of its 4-O-triphenylmethyl der ivative 19. Reaction of hydrazinopyridazines 20a,b with methyl 2,3-di- O-acetyl-L-threuronate (22), followed by treatment with bromine, gave the corresponding cetoxy-3-(s-triazolo[4,3-b]pyridazinyl-3)propanoic a cid methyl esters 24a,b. Acetonisation of o-s-triazolo[4,3-b]pyridazin yl-3)-D-gluco-pentitol (17a) gave a mixture of isomeric bis-acetonides 25 and 26, while acetonisation of o-s-triazolo[4,3-b]pyridazinyl-3)-D -manno-pentitol (18a) gave acetonide 27 as a single isomer.