US Patent 7501544 Process for the production of cyclic diketones

The present invention relates to a process for the preparation of compounds of formula (I), wherein the substituents are as defined in claim 1, by reacting a compound of formula (II), either with a chlorination or bromination agent or with a compound of formula (III) CI—SO2R9, R9 being C1-C4alkyl, C1-C4haloalkyl, phenyl or C1-C4alkyl-substituted phenyl, to form the compound of formula (IV), reacting the compound of formula (IV) with a compound of formula (V) M+-O−—C(O)—Y wherein Y is as defined above and M+ is the hydrogen cation or an alkali metal ion, alkaline earth metal ion or ammonium ion, to form the compound of formula (VI) and treating that compound with a cyanide source in the presence of a base.