| 摘要 |
<p>The invention relates to a process for the preparation of spiro[cis-4-(beta -hydroxyethyloxy) cyclohexane-[3H] -2' [1' H]-one derivatives of the formula (I) wherein R1 and R2 stand independently from each other for hydrogen, C1-4alkyl, C1-4alkoxy, C1-4alkylthio, C1-4polyfluroalkyl, C1-4polyfluroalkoxy, C3-7cycloalkyloxy, C3-7cycloakylthio, phenoxy, benzyloxy or nitro group by reduction of a dispiro [(1,3-dioxolane) -2, 4' -cyclohexane-1 ', 3"-[3H]indol] -2"[1"H]- one derivative of general formula (II), wherein R1 and R2 are as defined above, which comprises carrying out the reduction (a) with sodium cyanoborohydride in the presence of a Lewis acid, or (b) with sodium borohydride in the presence of a strong acid.</p> |
