39724-80-6Relevant articles and documents
Lewis Base-Catalyzed Enantioselective Conjugate Reduction of β,β-Disubstituted α,β-Unsaturated Ketones with Trichlorosilane: E/ Z-Isomerization, Regioselectivity, and Synthetic Applications
Sugiura, Masaharu,Ashikari, Yasuhiko,Takahashi, Yuka,Yamaguchi, Koki,Kotani, Shunsuke,Nakajima, Makoto
, p. 11458 - 11473 (2019/10/11)
The chiral bisphosphine dioxide-catalyzed asymmetric conjugate reduction of acyclic β,β-disubstituted α,β-unsaturated ketones with trichlorosilane affords saturated ketones having a stereogenic carbon center at the carbonyl β-position with high enantioselectivities. Because the E/Z-isomerizations of enone substrates occur concomitantly, reduction products with the same absolute configurations are obtained from either (E)- or (Z)-enones. Conjugate reduction is accelerated in the presence of an electron-rich aryl group at the β-position of the enone owing to its carbocation-stabilizing ability. Computational studies were also conducted in order to elucidate the origin of the observed enantioselectivity. The regio- and enantioselective reductions of dienones were realized and applied to the syntheses of ar-turmerone, turmeronol A, mutisianthol, and jungianol, which are optically active sesquiterpenes.
2,2-Dimethylsuccinic acid derivatives in isoprenoid synthesis: a 2,2-dimethylvinyl anion equivalent in the synthesis of ar-atlantone, ar-turmerone, and prenylated aromatic compounds
Strunz, George M.,Ya, Li
, p. 1317 - 1322 (2007/10/02)
The anion of methyl 2,2-dimethylsuccinate was alkylated with benzylic bromides to give the corresponding 3-substituted-2,2-dimethylsuccinates.Hydrolysis to the dicarboxylic acids, followed by bisdecarboxylation with lead tetraacetate, afforded 1-aryl-3-methyl-2-butenes, which are model prenylated aromatic compounds.Acylation of methyl-2,2-dimethylsuccinate with E-3-(4'-methylphenyl)crotonyl chloride gave the substituted succinate 9.Hydrolysis of the ester groups and acid-catalyzed decarboxylation of the resulting β-ketoacid produced the keto acid 10, which was decarboxylated by the Kochi method, furnishing ar-atlantone.Hydrogenatio n of 10 yielded 12, which on similar decarboxylation afforded ar-turmerone.
A New Synthesis of ar-E-Atlantone
Anand, R. C.,Ranjan, H.
, p. 994 - 995 (2007/10/02)
Conjugate addition to 2-methyl-6-p-tolyl-5-hexen-4-one (III) of methylmagnesium iodide in the presence of cuprous iodide furnishes 2-methyl-6-p-tolyl-4-heptanone which is transformed into title compound (I) through bromination and dehydrobromination.
