Simple and efficient routes for the preparation of isoxazolidinyl nucleosides containing cytosine and 5-methyl-cytosine as new potential anti-HIV drugs

A rapid and convenient large-scale strategy for the synthesis of some new i soxazolidinyl nucleosides, as potential antiviral drugs, is reported. In pa rticular, a multistep methodology based either on the 1,3-dipolar cycloaddi tion approach or on a slight modification of the convertible nucleoside con cept was exploited in the preparation of 4'-aza-2',3'-dideoxynucleoside, an alogues containing cytosine and 5-methyl-cytosine. (C) 2001 Elsevier Scienc e Ltd. All rights reserved.