3′-β-ethynyl and 2′-deoxy-3′-β-ethynyl adenosines: first 3′-β-branched-adenosines substrates of adenosine deaminase

The 3′-C-branched-adenosine and 2′-deoxyadenosine analogues 1–7 were tested as substrate of adenosine deaminase. The 9-(3′-C-ethynyl-β- -ribo-pentofuranosyl)adenine 1 and its 2′-deoxy analogue 7 were deaminated by the enzyme while the vinyl and ethyl derivatives 2 and 3 were not. The 9-(3′-C-branched-β- -xylo-pentofuranosyl)adenines 4–6 were deaminated by the deaminase.