| abstract |
The invention relates to a process for the preparation of a compound of the formula given. According to the invention, carbocyclic analogs are prepared to purine nucleosides of the formula I in which R 1 and R 2 each represent an optionally protected hydroxyl group, X represents a hydrogen atom or an optionally protected hydroxyl group and Y is guanin-9-yl, isoguanin-9-yl or hypoxanthine-9- yl is. They are prepared, for example, by subjecting a compound of the formula II, wherein R 1, R 2 and X have the abovementioned meaning, to the purine ring formation reaction. Formulas I and II |