Bicycloamide derivatives represented by the formulae (II-1), (II-2) and (II-3)
wherein R2, R3, R4 and R5 have the meanings given in the claims are useful intermediates for preparing carbocyclic nucleosides.
式 (II-1)、(II-2) 和 (II-3) 所代表的双环酰胺衍
生物
其中 R2、R3、R4 和 R5 具有权利要求中给出的含义,是制备碳环核苷的有用中间体。