Carbocyclic nucleoside drugs

Extending the aforementioned methodology from imidazole to adenine, the Tsuji-Trost reaction between the sodium salt of adenine and allylic acetate 66 gave 67 as a 82 18 mixture of cis trans isomers. Carbocyclic nucleoside 67 was advantageous over normal nucleosides as a drug candidate because it was not susceptible to degradation in vivo by nucleosidases and phosphorylases [52],... 

Scheme 13.43. The five-membered bicarbonate 160 was alkylated to give compound 161 in 97% chemical yield and 98% ee. Subsequently, the asymmetric allylic substitution of cyclopentene 161 with TMSN3 furnished azide 162 as a single diastereomer in 99% yield. A series of additional synthetic transformations was required to transform 162 to compound 163, a known intermediate in the synthesis of many bioactive carbocyclic nucleosides (e.g., carbovir, an anti-HIV drug).

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