3'-ETHYNYLCYTIDINE DERIVATIVE

摘要

Disclosed is a compound which has excellent anti-tumor activity and excel lent oral absorbability and is useful as an anti-tumor agent. Specifically d isclosed is a 3'-ethynylcytidine derivative represented by the general formu la (1) [wherein X represents a (substituted) alkylcarbonyl group, a (substit uted) alkoxycarbonyl group or a hydrogen atom; one of Y and Z represents a h ydrogen atom or a group represented by the formula: (R1)(R2)(R3)Si- and the other represents a group represented by the formula: (R4)(R5)(R6)Si-; and R1 , R2, R3, R4, R5 and R6 independently represent a (substituted) alkyl group, a (substituted) cyclic alkyl group or a (substituted) aryl group] or a salt thereof.