The key role of water in the heterogeneous permanganate oxidation of ω-hydroxy alkenes
作者:Sundarababu Baskaran、Imadul Islam、Padma S. Vankar、Srinivasan Chandrasekaran
DOI:10.1039/c39900001670
日期:——
Potassium permanganate–copper sulphate in dichloromethane in the presence of a catalytic amount of water effects a smooth oxidative cyclization of ω-hydroxyalkenes to ω-lactones in good yields with the net loss of one or more carbon atoms in the process.
Skeletal rearrangements during the lactonisation and intramolecular acylation of some branched-chain and cyclic alkenoic acids
作者:M. F. Ansell、J. E. Emmett、B. E. Grimwood
DOI:10.1039/j39690000141
日期:——
Skeletalrearrangements have been shown to occur when 4-methylhex-4-enoic, 5-methylhex-4-enoic, 3-cyclohexylprop-2-enoic, and 4-cyclopentylbut-2-enoic acids undergo lactonisation or intramolecularacylation in the presence of hot 50% sulphuric acid or hot polyphosphoric acid.
Enantioselective “clip-cycle” synthesis of di-, tri- and spiro-substituted tetrahydropyrans
作者:Khadra Alomari、N. Sai Pavan Chakravarthy、Bastien Duchadeau、Kristaps Ermanis、Paul A. Clarke
DOI:10.1039/d2ob00023g
日期:——
ω-Unsaturated alcohols were “clipped” via alkene metathesis to a thioester activating group, which was followed by a chiral phosphoric acid catalyzed intramolecular oxa-Michael cyclization to yield tetrahydropyrans and spiro-tetrahydropyrans with excellent enantioselectivity. The mechanism and origin of the enantioselectivity was probed by DFT calculations and kinetic isotope studies, where there was
Substituent directed oxidative cyclization with cetyltrimethylammonium permanganate: A general approach to the synthesis of γ- and δ-lactones
作者:Rajendra Rathore、Padma S. Vankar、S. Chandrasekaran
DOI:10.1016/s0040-4039(00)84916-3
日期:1986.1
Treatment of primary, secondary or tertiary γ- and δ-hydroxyolefins with cetyltrimethylammonium permanganate gives good yields of γ- and δ-lactones by oxidative cyclization, with loss of one carbon.