Synthesis of new nucleoside analogues comprising a geminal difluorocyclopropane moiety as potential antiviral/antitumor agents

Geminal difluorocyclopropane analogues of nucleosides 7a - 7e were synthesi zed. Compounds 7a and 7c - 7e were obtained by alkylation of nucleic acid b ases or their appropriate precursors with (cis)-1-benzyloxymethyl-2-bromome thyl-3,3-difluorocyclopropane (8). Analogue 7b was prepared by hydrolysis o f 2-amino-6-chloropurine derivative 7e. Compounds 7a - 7d did not exhibit a ny antiviral activity against HCMV, HSV-1, HSV-2 EBV, VZV, HBV and HIV-1 or antitumor effects against murine leukemia L1210, mouse tumors PO3 or C38 a nd human tumor H15.