14387-99-6Relevant articles and documents
Conversion of α,β-Unsaturated Esters to Their β,γ-Unsaturated Isomers by Photochemical Deconjugation
Duhaime, Randy M.,Lombardo, Domenic A.,Skinner, Ian A.,Weedon, Alan C.
, p. 873 - 879 (2007/10/02)
It is shown that the α,β-unsaturated esters 1, 2, 4, 5, 6, 16, and 18, which have been reported to be inert to photochemical deconjugation or to undergo the reaction inefficiently, can be converted to their β,γ-unsaturated isomers in good yield if the irradiation is performed in the presence of a catalytic amount of a weak base such as 1,2-dimethylimidazole.It is also shown that addition of catalytic amounts of base can alter the product distribution in cases such as 11, 23, and 26 where more than one isomer can be formed.
HOMOLYTIC DISPLACEMENT AT CARBON. V. FORMATION OF CYCLOPROPYLCARBINYLSULPHONES AND TRICHLOROETHYLCYCLOPROPANES FROM BUT-3-ENYL COBALOXIMES BY A NOVEL PROCESS INVOLVING HOMOLYTIC ATTACK AT THE δ-CARBON OF THE BUTENYL LIGAND
Ashcroft, Martyn R.,Bury, Adrian,Cooksey, Christopher J.,Davies, Alwyn G.,Gupta, B. Dass,et al.
, p. 89 - 104 (2007/10/02)
But-3-enyl- and substituted but-3-enylcobaloximes react with bromotrichlormethane (or trichloromethanesulphonyl chloride) and with 4-toluenesulphonyl chloride thermally or photochemically to give good yields of β,β,β-trichloroethylcyclopropanes and cyclopropylcarbinyl(tolyl)sulphones, respectively.The reactions proceed by a chain mechanism in which a key step is a novel process in which homolytic attack of a trichloromethyl or 4-toluenesulphonyl radical at the δ-carbon of the butenyl ligand leads to synchronous or subsequent attack of the incipient γ-carbon radical on the α-carbon, causing cyclisation and displacement of cobaloxime(II).The other propagation step involves the reaction of the cobaloxime(II) with the bromotrichloromethane, trichloromethanesulphonyl chloride or 4-toluenesulphonyl chloride to give the reactive organic radical.
