Method for the production of optically active alpha alkyl carbonyl compounds

Method for the production of compounds of the formula I:

• wherein a compound of the formula II,
• is reacted with R4MgX and ZnY2 or R4MgX and ZnR42, with inversion of the stereoconfiguration at the α-carbonyl carbon atom, to give a compound according to formula I,
• in which R1 is OM, O—R5 or NR5R6, where M is a metal ion and R5 and R6, independently of one another, represent a straight-chain or branched alkyl radical, alkenyl radical, arylalkyl radical, aryl radical or heteroaryl radical,
• in which R2 is a sulphonate leaving group, phosphate leaving group, carboxylate leaving group, carbamate leaving group, carbonate leaving group or a halide,
• in which R3 represents a straight-chain or branched alkyl radical, alkenyl radical, arylalkyl radical, aryl radical or heteroaryl radical which optionally has 5-7 carbon atoms and 1-2 hetero atoms, selected from O, N, P and S, as substituents or are interrupted by the hetero atoms,
• in which R4 represents a straight-chain or branched alkyl radical, alkenyl radical, arylalkyl radical, arylradical or heteroaryl radical,
• in which, in R1 to R6, an alkyl radical has 1-15 carbon atoms, an alkenyl radical 2-15 carbon atoms, an arylalkyl radical 5-15 carbon atoms, an aryl radical 5-10 carbon atoms and a heteroaryl radical 5-8 carbon atoms and 1-2 hetero atoms, selected from O, N, P and S,
• in which X represents a halogen and
• in which Y represents a sulphonate, a sulphate, a carboxylate, an alcoholate, a nitrate, a chalcogen or a halogen.