Patent ID: 6699911
Filing Date: 2004-03-02
Classification: C07C,Y02P

Abstract:
A process for the preparation of cyclohexene derivatives of general formulae I or II: in which the substituents R1 and R2 independently of one another are defined as follows: R1 is R2 is OH or a protective group convertible to a hydroxyl group by hydrolysis; R3 and R4 are hydrogen or C1-C4-alkyl; and R5 is hydrogen or C1-C4-acyl, by the reduction of alkyne compounds of general formulae III or IV: in which the substituents R1 and R2 are as defined above, wherein the reducing agent used is a mixture of zinc and at least one compound B selected from the group consisting of ammonium salts, copper salts and alkali metal and alkaline earth metal salts.