PHOTOISOMERIZATION OF TRI-T-BUTYLBENZENES . PHOTOCHEMICAL INTERCONVERSION OF BENZVALENES

The previously unreported 1,2,4-tri-r-butylbenzvalene (VI) is formed with a quantum yield of 0.12 as the only initial product in the photolysis of 1,3,5-tri-t-butylbenzene (V) in isohexane at 2537 Å. It is also formed, together with 1,2,4-tri-t-butylbenzene (IV) and V, by photolysis of 1,3,6-tri-t-butylbenzvalene (I). Although it has not been isolated, VI has been found to rearomatize to V with a half-life of 17 min at 24.5°, to react with alcohols to yield 4-alkoxybicyclo[3.1.0]hexenes, and to photolyze to I, IV, and V. © 1968, American Chemical Society. All rights reserved.