Cis -5- [1- (4-chlorophenyl) - methylene] -1-hydroxy-2,2-dimethyl-cyclopentanol manufacturing method of

[Formula 1] The present invention comprises the reaction of the formula (Va) or (Vb) epoxy alcohol, or mixtures thereof with an alkali metal borohydride or alkali borohydride earth, especially sodium borohydride and anhydrous aluminum chloride (III) diol of formula (Ia) or (Ib), or a method for producing the mixture. The present invention also relates to processes and intermediates for producing the epoxy alcohol of formula (Va) or (Vb). The invention further cis-diol of formula (Ia) or (Ib) is applied as a precursor - relates to a process for producing metconazole. .BACKGROUND