Process for preparing cis-5-1-(4-chlorophenyl)-methylene-1-hydroxymethyl-2,2-dimethylcyclopentanol

摘要

The present invention relates to a process for preparing a diol of the formulae (Ia) or (Ib), or a mixture thereof,; ;comprising the reaction of an epoxy alcohol of formulae (Va) or (Vb), or a mixture thereof,; ;with alkali metal borohydride or earth alkaline borohydride, in particular sodium borohydride, and anhydrous aluminum(III) chloride.;The invention also relates to processes and intermediates for preparing an epoxy alcohol of formulae (Va) or (Vb). The invention furthermore relates to processes for preparing cis-metconazole in which a diol of the formulae (Ia) or (Ib) is applied as a precursor.