Synthesis of Benzyl and Benzyloxycarbonyl Base-Blocked 2'-Deoxyribonucleosides

Article abstract of DOI:10.1021/jo00144a014

Acylimidazoles have been alkylated with trialkyloxonium tetrafluoroborates to form acylimidazolium salts.These salts, particularly (benzyloxycarbonyl)imidazolium salts, are shown to be effective agents for the direct, mono-N-protection of deoxynucleosides as their acyl derivatives.These acyl nucleosides are also available via thiocarbamate intermediates.Thus 3',5'-bis(tert-butyldimethylsilyl)-2'-deoxyguanosine (4b), on treatment with phenyl chlorothioformate, gave the 6-thiophenyl-substituted purine 38a.The thiophenyl group of 38a can be replaced by hydrogen, amino, and alkoxy groups to give a variety of substituted purine deoxyribonucleosides.