| 摘要 |
<p>A method for the preparation of acyclic nucleosides such as valomaciclovir stearate comprising the acid hydrolysis of an intermediate of the formula II: where X is a leaving group or an optionally protected guanine moiety, R1 is a hydroxy protecting group or a -C(=O)C1-C22 alkyl ester group; R2 and R3 are independently lower alkyl or benzyl, or R2 and R3 taken together are -CH2CH2- or -CH2CH2CH2- or -CH2CH2CH2CH2-; to the corresponding aldehyde of the formula III: and the reduction of the aldehyde to the corresponding alcohol of the formula IV: by the addition of a borohydride or borane aldehyde reducing agent, characterised in that the borohydride or borane aldehyde reducing agent is introduced under acid conditions.</p> |
