Double Protection of the Heterocyclic Base of Xanthosine and 2′-Deoxyxanthosine

Abstract

Reaction of O-protected xanthosines with p-nitrophenyl ethanol under Mitsunobu conditions yields the doubly alkylated O²,O⁶- and N¹-,O²-derivatives. Deoxyxanthosine protected on both oxygens with a 2-(4-nitrophenyl)-ethyl group was synthesized starting from deoxyguanosine. Both protecting groups can be eliminated with DBU in pyridine.