Synthesis of Novel Carbovir Analogue

摘要

The synthesis of 4'-phenyl and 1'-methyl doubly branched carbocyclic nucleoside was accomplished from 2-hydroxy acetophenone.The 4'-phenyl group was installed via a [3,3]-sigmatropic rearrangement reaction,and the carbonyl addition of methylmagnesium bromide was used to introduce the 1'-methyl group.Cyclization of divinyl 9 was performed using 2nd generation Grubbs catalyst.The coupling of cyclopentenol 12a with 6-chloropurine by Mitsunobu reaction and desilylation was used to synthesize the target nucleoside 15.