98017-85-7Relevant articles and documents
Homolytic Displacement at Saturated Carbon: Part 5. Synthesis of Cyclopropylmethyl, Bicyclohex-2-yl, Bicyclohept-2-yl and Cyclohexanespirocycloprop-2-yl Sulphones from the Corresponding But-3-enylcobaloximes
Gupta, B. Dass,Das, Indira,Dixit, Vandana
, p. 2409 - 2446 (2007/10/02)
But-3-enylcobaloxime reacts with arenesulphonyl chlorides under thermal and photochemical conditions to give cyclopropylmethyl sulphones.The yields depend upon the reaction conditions used.Similar reactions of cyclopent-2-enylmethylcobaloxime and cyclohex-2-enylmethylcobaloximes under photochemical conditions form a mixture of cis and trans isomers of bicyclohex-2-yl and bicyclohept-2-yl sulphones in (50:50) and (70:30) isomeric ratios respectively.However, cyclohex-3-enylcobaloximes form only the trans-bicyclohex-2-yl sulphone.Exclusive formation of cycloalkanespirocycloprop-2-yl sulphones is observed in the reactions of 2-(cyclo alk-1-enyl)ethylcobaloximes with arenesulphonyl chlorides.The reactions are free radical in nature and are believed to take place by a chain mechanism.In the key step a homolytic attack of the RSO2 radical at the terminal (δ) carbon of the butenyl ligand leads to the cyclized product.The exact nature of the ring closure step is uncertain, as both concerted and stepwise mechanisms are possible.