Li L, Cai P, Xu D, Guo Q, Xue S. Zinc-Mediated C−C Bond Sigmatropic Rearrangement: A New and Efficient Methodology for the Synthesis of β-Diketones.
J Org Chem 2007;
72:8131-4. [PMID:
17887703 DOI:
10.1021/jo7013627]
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Abstract
A new and efficient methodology has been developed for the synthesis of beta-diketones from aromatic alpha-bromo ketones in the presence of Furukawa reagent under mild conditions. The present transformation is proposed to proceed via a Reformatsky-type reaction of alpha-bromo ketones, followed by C-C bond sigmatropic rearrangement of the aldolate intermediate to give beta-diketones in moderate to good isolated yields, while aliphatic alpha-bromomethyl ketones resulted in the formation of 2,4-disubstituted furans or cis-1,2-disubstituted cyclopropanols in moderate yields. The scope of this process was investigated, and a tentative mechanism was proposed.
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