Ring synthesis adenine, 2-methyl

Methyl oxetane-2-carboxylate derivatives (e.g., 284), obtained by ring contraction of aldonolactones, have been employed for the synthesis (279) of the nucleoside / -noroxetanocin [9-(/ -D-eryt/iro-oxetanosyl)adenine, 304] and its a-anomer via an a-chloride obtained by a modified Hunsdiecker reaction. Displacement of chloride by adenine and debenzylation gave 304. The threo isomer of304, /J-epinoroxetanocin (305), was likewise synthesized from D-lyxono-1,4-lactone. The oxetane nucleosides display potent antiviral activity against the human immunodeficiency virus (HIV). 

---