Verbindungen von Pyrimidin 2'-Methylidin Nukleosiden

Pyrimidine 2 min -deoxy-2 min -methylidene nucleoside compounds : wherein R represents amino, hydroxy, silylamino, silyloxy, acylamino or acyloxy; R represents hydrogen, halogen, a lower alkyl, a lower alkenyl, a lower alkynyl or haloalkyl; R and R represent the same or different hydrogen, silyl, acyl or aminoacyl, or a pharmaceutically acceptable salt or hydrate thereof, except that R is amino or hydroxy, and both of R and R are hydrogen. Said compounds possess excellent antitumor and antiviral activities, thus providing novel anticancer and antiviral agent.