81462-39-7Relevant academic research and scientific papers
Photochemistry of chloro-2-vinylstilbenes
Brouw, P. M. op den,Laarhoven, W. H.
, p. 58 - 67 (2007/10/02)
Short irradiation at 300 nm of α-chloro- and β-chloro-2-vinylstilbene (20 and 21) leads to a mixture of 2-vinyltolane (35) and 2-vinylstilbene (1) accompanied by the cis- and trans-isomers of the starting compounds.Evidence is found for the occurrence of an ionic intermediate during the photolysis of 20 in methanol.At 360 nm, an additional, small amount of 1-chloro-endo- and 1-chloro-exo-6-phenylbenzobicyclohex-2-ene (39) is formed formed from 20.The elimination of hydrogen chloride also occurs during the irradiation of 2-(2-chlorovinyl)stilbene (23) and leads to 2-ethynylstilbene (41).The acetylenic compounds are photocyclized into 2-phenylnaphthalene (38).However, 2-(1-chlorovinyl)stilbene (22) reacts without loss of chlorine to give 1-chloro-exo-5-phenylbenzobicyclo-hex-2-ene (40).This exceptional reaction mode is due to a much higher rate of photocyclization resulting from less distortion in the stilbene moiety and a preference for a conformation better suited to the reaction of the 2-(1-chlorovinyl)stilbene molecule.It is shown that both isomers of 22 can photocyclize into 40.
