| abstract |
The present invention relates to a process for producing an acylated cyclic diketone compound, this being substantially a substituted benzoyl derivative of a 1,3-cyclohexanedione, characterized by the rearrangement of the corresponding enol ester, in which the rearrangement is conducted in the presence of a source of cyanide, which is an alkali metal cyanide, an alkylmethyl ketone cyanohydrin having 1 to 4 carbon atoms in the alkyl group, benzaldehyde cyanohydrin, cyclohexanone cyanohydrin, a cyanohydrin of an aliphatic aldehyde with C2- C5, lactonitrile, a lower alkyl silyl cyanide, potassium ferricyanide, or hydrogen cyanide, where such rearrangement is conducted at temperatures up to 80 degrees C in the presence of either (a) a catalytic amount of a cyanide source and an excess molar, with respect to the enol ester, of a moderate base; or b) a stoichiometric amount, relative to the enol ester, of potassium cyanide or lithium cyanide and a catalytic amount of a Crown cyclic ester or an acyclic analog thereof. |