Nucleosides. 3. Reactions of AICA-Riboside with Isothiocyanates. A Convenient Synthesis of Isoguanosine and Xanthosine Derivatives

Article abstract of DOI:10.1021/jo00013a026

Cyclodesulfurative annulations of 5-<1-(3-substituted-thioureido)>-1-(β-D-ribofuranosyl)imidazole-4-carboxamides (3a-h) with N,N-dicyclohexylcarbodiimide are described.Isoguanosine (4) and several 1-substituted isoguanosines 6a-f,h are readily prepared by a ring closure of the appropriate resulting 5-(3-substituted-1-ureido)-1-(β-D-ribofuranosyl)imidazole-4-carbonitriles 5a-h.Treatment of the appropriate 1-substituted isoguanosines under basic conditions has furnished the corresponding 1-substituted xanthosine 12.