SYNTHESES OF C-NUCLEOSIDES AND N-NUCLEOSIDES FROM 1-AZA-2-AZONIAALLENE AND 1,3-DIAZA-2-AZONIAALLENE SALTS

C-Nucleosides are prepared by cycloaddition of 1-aza-2-azoniaallene sa lts 2 and 1,3 -diaza-2-azoniaallene salts 5 to the triple bonds of a g lycosylalkyne and of glycosyl cyanides, Thus, the glucosylalkyne 7 rea cts with salts 5 to give the 4-glucosyl-1,2,3-triazolium salt 8, From the galactosyl cyanide 9, the ribofuranosyl cyanide 13, and several 1- aza-2-azoniaallene salts 2 the glycosyl-1,2,4-triazoles 11, 15, 17 are obtained, Deacylation affords the free C-nucleosides 12, 16, 18, Cycl oaddition to the C=S double bond of the glucosyl isothiocyanate 19 fur nishes glucosylimino-1,3,4-thiaziazoles 20-22. A new method for the pr eparation of the isothiocyanate 19 is described.