Patent ID: 7279605

Claim:
A process for the preparation of a compound of formula wherein R represents a C 1-8 alkyl or alkenyl group optionally substituted or a C 5-6 aromatic, optionally substituted; and R 1 , R 2 , R 3 and R 4 represent, simultaneously or independently, a hydrogen atom, a C 1-8 alkyl or alkenyl group optionally substituted or a C 5-6 aromatic group, optionally substituted; the process comprising the reaction between an enone of formula wherein R, R 1 , R 3 and R 4 have the same meaning as in formula (I); with an aldehyde of formula wherein R 2 has the same meaning as in formula (I); and the reaction between the enone (II) and the aldehyde (III) being performed in the presence of a catalytic system comprising: i) at least one metal complex of formula M(OR 5 ) 4-n X n (IV) wherein M is Ti(IV) or Zr(IV), R 5 represents a C 1-6 linear or branched alkyl group, X represents a halide and n represents an integer from 1 to 3; and ii) at least one co-ingredient selected from the group consisting of a) an alkyl or aromatic carboxylic acid anhydride containing 2 to 10 carbon atoms; b) an anhydrous sulfate, chloride or bromide of a metal cation selected from the group consisting of Li + , Na + , K + , Cs + , Mg 2+ , Ni 2+ , Ca 2+ , Zn 2+ , Fe 3+ and Al 3+ ; c) an insoluble inorganic material capable to form a chlatrate with water; and d) a C 4 -C 15 orthoester, BF 3 , N-methyl-N-trimethylsilyl-trifluoroacetamide, 1-trimethylsilylimidazole and ClSi(R 6 ) 3 , R 6 representing a C 1-5 alkyl group.