Cooperation of Cis Vicinal Acceptors for Donor–Acceptor Cyclopropane Activation: TfOH-Promoted Ring-Opening/Aryl Shift Rearrangement to 3- and 5-Ylidenebutenolides
Carbonyliron Complexation and Carbonyl Insertion of Allenic Ketones
作者:Latchezar S. Trifonov、Alexander S. Orahovats、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.19920750613
日期:1992.10.2
The allenic α-ketones 5a–f give, on irradiation in the presence of [Fe(CO)5], the bis(tricarbonyliron) complexes 6a–f. In the case of ketone 5e, a minor bis(tricarbonyliron) complex with the proposed unique structure 8 is also obtained. Ketones 5a–d, which are disubstituted at C(4), under the same conditions, afford also the lactones 7a–d in moderate yields. The latter reaction is a new carbonyliron-mediated
proximity-driven, Pd(II)- or Cu(I)-catalyzed intramolecular ketone haloacylation, regio- and stereoselective heterolytic ring-opening 1,5-haloacylation of cyclopropyl ketones, including those with weak single alkyl donors, has been developed for the synthesis of valuable α-quaternary halo-γ-butenolides. The vicinal carboxylic acid and ketone acceptors are no longer just spectator activators. Further
The chemical behavior of 2-methylene-2,3-dihydro-3-furanones
作者:N. M. Igidov、E. N. Kozminykh、G. A. Shavkunova、V. O. Kozminykh、E. S. Berezina
DOI:10.1007/bf00702145
日期:1995.2
Diphenylketene undergoes regioselective thermal [2+2]-cycloaddition to the heterocyclic C(3)=O carbonyl group of 5-aryl-2-methoxycarbonylmethylene-2,3-dihydrofuran-3-ones and 5-phenyl-2,3-dihydrofuran-2,3-dione to give the corresponding 3-diphenylmethylene derivatives of 2,3-dihydrofuran.
——
作者:S. N. Shurov、I. A. Zhikina、I. B. Podvintsev
DOI:10.1023/a:1020303507606
日期:——
3-Reactions of 5-aryl, 5-heteryl, and 5-styryl-2,3-dihydro-2,3-furandiones with phenylbenzoyldiazomethane gave rise to 5-substituted 3-dipenylmethylene-2,3-dihydro2-furanones. The possible intermediates and reaction products were investigated by semiempirical SCF MO LCAO method in AM1 approximation.