- Reaction of Thioketones with Carbonyl Oxides and 3,3-Dimethyl-1,2-dioxirane. Cycloaddition vs. Oxygen Atom Transfer
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The ozonolysis of vinyl ethers 1a, b in the presence of adamantane-2-thione 4a and bicyclononan-9-thione 4b gave in each case the corresponding thioozonides 5a-c in moderate yields, whilst ozonolysis of a mixture of vinyl ethers 1a-d and thiobenzophenone derivatives 4f-h gave the corresponding thione S-oxides 8f-h in isolated yields of 10-40percent, together with the benzophenones 7f-h. 3,3-Dimethyl-1,2-dioxirane, generated in situ from the reaction of acetone and 'oxone' (2KHSO5-KHSO4-K2SO4), transferred an oxygen atom to compounds 4a, f, g, i providing the thione S-oxides 8a, f, g, i in 29-97 percent yield.
- Tabuchi, Toshihiko,Nojima, Masatomo,Kusabayashi, Shigekazu
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p. 3043 - 3046
(2007/10/02)
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- Photochemical Oxidation of Thioketones: Steric and Electronic Aspects
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Oxidation of diaryl, aryl alkyl, and dialkyl thioketones by singlet oxygen generated via self-sensitization and other independent methods yielded the corresponding ketone and sulfine in varying amounts.A zwitterionic/diradical intermediate arising out of the primary interaction of singlet oxygen with the thiocarbonyl chromophore is believed to be the common intermediate for the ketone and sulfine.While closure of the zwitterion/diradical to give 1,2,3-dioxathietane would lead to the ketone, competing oxygen elimination is believed to lead to the sulfine.This partitioning is governed by steric and electronic factors operating on the zwitterionic/diradical intermediate.
- Ramnath, N.,Ramesh, V.,Ramamurthy, V.
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p. 214 - 222
(2007/10/02)
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- STERIC ASPECTS OF THE OXIDATION OF THIOKETONES BY SINGLET OXYGEN
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Singlet oxygen oxidation of dialkyl thioketones yields the corresponding ketones and in some cases sulfoxides in varying amounts.Steric considerations on the reactive zwitterionic/diradical intermediates have been invoked to rationalise the product distribution.
- Ramnath, Narayan,Jayathertha, Vaidhya Rao,Ramesh, Varadaraj,Ramamurthy, Vaidhyanathan
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