Alcohols various photochemical deriv

Osuka etaL described the type 11 photoreaction of various homonaphthoquinones 22a-d with abstractable y-hydrogens. The photochemical behavior of these substrates is very dependent on the cyclopropane substituents (R and R ). Irradiation of 22a (R = H, R = CH,) gave the usual cyclobutanol 23a along with the unsubstituted alcohol 24a (Scheme 14). The compound 24 may be derived by hydrogen transfer from a 8-carbon to the less reactive ketyl radical center of the primary biradical VII. It was confirmed that a photoequilibrium takes place between 22 and 23 via VII as a common intermediate. 

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