Adenosine arabinoside Ara

The introduction of an azido substituent on the C-2 position of cytosine arabinoside (ara-C) (149) or adenosine arabinoside (ara-A) (154) has been found to confer favourable properties to these antimetabolites. Ara-C, one of the most effective drugs for the treatment of human acute myeloblastic leukaemia [176], is subject to rapid metabolic deamination, by deoxycytid-ine deaminase, to the inactive uridine derivative ara-U (152) Scheme 3.5), and the drug has a half-life of approximately 12 minutes in man [177]. Efforts to circumvent this problem by modifying the 2 -arah/ o-position led... 

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