- Preparation of 3-Substituted 4-Thianones and Their 1,1-Dioxides via Palladium Mediated Deallyloxycarbonylation
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3-Alkyl-4-thianones 4 (3-alkyl-thiacyclohexan-4-ones) can be conveniently prepared by the alkylation of 3-allyloxycarbonyl-4-thianone (1b) followed by deallyloxycarbonylation mediated by tetrakis(triphenylphospine)palladium in the presence of morpholine.The corresponding sulphones 9, as well as 2,3-dialkyl-4-thianone derivatives 12 and 13 can be prepared by analogous procedures.
- Casy, Guy,Sutherland, Alan G.,Taylor, Richard J. K.,Urben, Peter G.
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p. 767 - 769
(2007/10/02)
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- A Regioselective Synthesis of Cyclopentenones from 4-Thianone
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Alkyl-substituted 3-cyclopentenones 4 and 5 were prepared in moderate to good yields starting from 4-thianone by the selective alkylation and Ramberg-Baecklund-type reactions.One route starts with 6-alkyl-1,4-dioxa-8-thiaspirodecane 8,8-dioxides (8) and another with 7-alkyl-1,4-dioxa-7-(p-tolylsulfonyl)-8-thiaspirodecane 8,8-dioxides (15), followed by acid-catalyzed cleavage of the 1,3-dioxolane ring of 1,4-dioxaspironon-7-enes 9 and 16 to afford 4 and 5.
- Matsuyama, Haruo,Miyazawa, Yasuyuki,Takei, Yuji,Kobayashi, Michio
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p. 1703 - 1710
(2007/10/02)
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- S-Alkyl-4-oxothianium Ions for the Synthesis of Cyclopentenones. Acid-Catalyzed Cyclization of Divinyl Ketones
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A new approach to 2-cyclopentenones via an acidic cyclization of divinyl ketones by the use of S-alkyl-4-oxothianium ions as key compounds is described.
- Matsuyama, Haruo,Takei, Yuji,Kobayashi, Michio
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p. 2657 - 2659
(2007/10/02)
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- TETRAHYDROTHIOPYRAN-4-ONE. A USEFUL 5 C SYNTHON FOR THE SYNTHESIS OF 3-CYCLOPENTENONES
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2-Alkyl-3-cyclopentenones were prepared in moderate yields starting from tetrahydrothiopyran-4-one by the one-pot Ramberg-Baecklung reaction of 6-alkyl-1,4-dioxa-8-thiaspirodecane-8,8-dioxides, followed by acid catalyzed de-dioxolanation.
- Matsuyama, Haruo,Miyazawa, Yasuyuki,Takei, Yuji,Kobayashi, Michio
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p. 833 - 836
(2007/10/02)
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