Studies of nucleosides and nucleotides—LXXIV : Purine cyclonucleosides—34 a new method for the synthesis of 2'-substituted 2'-deoxyadenosines

Abstract

8,2'-O-Cycloadenosine was protected at 3' and 5'-OHs with acetyl groups and cleaved using liq. H 2S. Subsequent dethiolation and mesylation gave 2'-O-mesyl-3',5'-di-O-acetyl-arabinosyladenine ( 6). When 6 or its deacetylated parent compound ( 7) was heated with sodium azide in DMF, 3'-azido-3'-deoxyxylofuranosyladenine ( 9) was the only product. The cyclonucleoside was then protected with tetrahydropyranyl groups and subjected to a similar series of reactions as above to give 2'-O-mesyl-3',5'-di-O-tetrahydropyranylarabinosyladenine ( 14). The compound 14 was heated with sodium azide after which acidic deprotection afforded 2'-azido-2'-deoxyadenosine ( 16). Hydrogenation of 16 gave 2'-amino-2'-deoxyadenosine ( 18). 2'-Chloro-2'-deoxyadenosine ( 19) was also obtained by treatment of 14 with lithium chloride and subsequent deprotection. UV, IR and NMR spectral data of these compounds are described.