摘要:
                                Synthesis of 3-methyl-3-deazainosine (7a) and 3-ethyl-3-deazainosine (7b) can be done by intramolecular cyclization of 5-iodoimidazole-4-(N-allyl and -crotyl)carboxamide ribosides 4a,b with palladium catalysts. The glycosyl conformer population of 7a,b was analyzed by NOE experiments to be fixed in anti-conformation.