| abstract |
A process for the preparation of a derivative of 2 ', 3'-didehydro-2', 3'-dideoxynucleoside of formula III: (CF DRAWING IN BOPI) characterized in that it comprises the reaction of a compound I having the following formula: (CF DRAWING IN BOPI) with a viologen (salt of N, N'-dialkyl-4,4'-dipyridinium II having the following formula: (CF DRAWING IN BOPI) Formulas in which, R ** 1 represents a C1 -C1 2 -acyl group or a sulfonyl group; R2 represents a hydrogen atom, a C1 -C1 2 -acyl group, a C1 -C1 2 -alkyl group, a C6 -C1 8 -aralkyl group or a silyl group ; R ** 3 represents a C1 -C2 O -alkyl group or a C6 -C20 -aralkyl group; X and Y which may be the same or different, each represent a halogen atom; B represents a purine base, a base pyrimidine, an imidazole base or a triazole base attached by its 1 position to the sugar residue. |