| abstract |
A purine salt of the formula is described: wherein Y1 is chlorine, bromine, or iodine, and R1, R2, R3, and R4 are independently selected from alkyl and substituted alkyl, the salt is reacted with the compound of the formula to produce the purine of the formula: where X is a leaving group, and Z1 is a protected form of the Z carbohydrate substitute. Several routes are described for the conversion of this intermediate to the antiviral agent. |