79598-11-1Relevant articles and documents
Stable Enols of α-dibenzoylmethanes
Regitz, Manfred,Schaefer, Ansgar
, p. 1172 - 1185 (2007/10/02)
The enols 13a-m of α-(aryloxy)- and α-(alkyloxy)dibenzoylmethanes 4a-m are obtained by decomposition of the copper chelates 11a-m with sulfuric acid.The copper compounds are synthesized either by ester condensation of the acetophenones 6h-m with phenyl benzoate (7) or by nucleophilic substitution of α-bromodibenzoylmethane (9) with the phenols 10a-g.The enolates 8, primarily formed in the presence of sodium hydride or triethylamine, respectively, are directly converted into the chelates 11 with copper(II) acetate.The enols 13 are characterized by isomerization to the β-diketones 4 as well as by bromination to 12.