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A novel route to synthesize 1,4‐dicarbonyl compounds is described. α,α‐Dibromoketones generate zinc enolates through a diethylzinc‐mediated halogen‐metal exchange and react with α‐bromocarbonyl compounds to furnish 1,4‐dicarbonyl compounds via a second generation of zinc enolates. This cross‐coupling reaction is enabled by the chemoselective formation of zinc enolates from α,α‐dibromoketones in the presence of α‐bromocarbonyl compounds. Chiral 1,4‐dicarbonyl compounds can be obtained via the enantioselective bromination of aldehydes using a chiral secondary amine catalyst and a subsequent cross‐coupling reaction between the resulting chiral α‐bromoaldehydes and α,α‐dibromoacetophenones. [ABSTRACT FROM AUTHOR]

We report a range of highly regioselective openings of [1.1.1]propellane with various allylic zinc halides, as well as zinc enolates of ketones, esters and nitriles. The resulting zincated bicyclopentanes (BCPs) were trapped with a range of electrophiles including acyl chlorides, sulfonothioates, hydroxylamino benzoates, tosyl cyanide as well as aryl and allyl halides, generating highly functionalized BCP‐derivatives. The unusually high regioselectivity of these reactions has been rationalized using DFT calculations. A bioisostere of the synthetic opioid pethidine was prepared in 95 % yield in one step using this method. [ABSTRACT FROM AUTHOR]

Chiral N-( tert-butyl)sulfinyl aldimines easily prepared from commercially available compounds have been used as starting materials for the following processes: (i) hydrogen transfer, (ii) addition of zincates, (iii) In-promoted allylation, and (iv) addition of zinc enolates. In all cases, the final desulfinylation to yield the expected chiral α-substituted primary amines was easily performed with hydrochloric acid in an organic solvent. This methodology has been successfully applied to the preparation of chiral natural products such as alkaloids and amino acids. [ABSTRACT FROM AUTHOR]

single crystal X-ray diffraction study of the crystals of methyl 4-methyl-3,5-dioxo-1-phenyl-2-oxaspiro[5.5]undecane--carboxylate shows that phenyl and methoxycarbonyl substituents are in the equatorial position on the one side of the dioxopyran ring with twist boat conformation. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor of "Chemistry of Heterocyclic Compounds" concerning selective cyclopropanation of chromenes with a phenylacryloyl substituent by bromine-containing zinc enolates.