27538-13-2Relevant articles and documents
Alkynes and Cumulenes, XIV. - Thermal and Photochemical Dimerization of 1,2,4-Pentatriene (Vinylallene)
Schneider, Ralf,Siegel, Herbert,Hopf, Henning
, p. 1812 - 1825 (2007/10/02)
On heating at 170 degC in the gas phase 1,2,4-pentatriene (1) dimerizes to the six-membered hydrocarbons 2, 5, and 13, to the eight-membered ring hydrocarbons 8 and 18 as well as to the tetrahydronaphthalene 16; in a side reaction 1 cycloisomerizes to 3-methylene-1-cyclobutene (11).The C10H12-hydrocarbons are very likely produced via diradical intermediates, only 2, 5, and 13 being primary products.On the other hand, for the dimers 8, 16, and 18 reasonable electrocyclic reaction paths may be postulated.The sensitized photodimerization of 1 leads to the cyclobutane derivatives 31, 33, 35 and to 28 as a thermally produced secondary product from 33.The exclusive cyclobutane formation suggests that 1 behaves analogously to 1,3-butadiene in sensitized photodimerizations.
