51302-77-3Relevant academic research and scientific papers
Photochemistry of Alkenes. 9. Medium-sized cycloalkenes
Kropp, Paul J.,Mason, J. Derek,Smith, Gardiner F. H.
, p. 1845 - 1849 (2007/10/02)
The behavior of three medium-sized cycloalkenes cyclooctene (10), cyclodecene (17) and cyclododecene (21) on direct irradiation in pentane and methanol solution has been studied.The results are summarized in Tables 1-3.Irradiation of medium-sized cycloalkenes is a convenient procedure for the preparation of bicyclic products (cf. 13, 14, 19, 20 and 23) through transannular insertion reactions of carbene intermediates (cf. 11, 18, and 22) thought to arise from rearrangement of the 1 state via a 1,2-hydrogen shift.The formation of trans-decalin (20) is in contrast to the reported formation of the cis isomer on base-initiated decomposition of the corresponding tosylhydrazone.None of the three cycloalkenes 10, 17, or 21 underwent competing nucleophilic trapping of the 1 state in methanol, in contrast with other alkenes previously studied.However, cyclododecene (21) afforded the methyl ether 25, which apparently resulted from protonation of the 1(?,?*) state, and the epoxide 26, which is thought to arise from electron transfer to oxygen by the 1 state followed by protonation of the resulting superoxide ion and oxidation of unreacted cyclododecene (21).
