Influence of the β-Substitution on the Photochemistry of α,2-Diacetoxystyrenes. Irradiatin of Phenyl, Vinyl, and Benzyl Derivatives

Article abstract of DOI:10.1007/BF00808927

β-Substitution shows a pronounced influence on the photochemistry of α,2-diacetoxystyrenes.As in the case of the parent compound, intramolecular cyclization with participation of the neighbouring 2-acetoxy group takes place upon irradiation of the enol esters 4a-c; however other processes are also observed, depending on the substrate.The phenyl derivative 4a gives the E isomer 7a and the phenanthrene 9.The vinyl derivative 4b also undergoes cis-trans isomerization and/or photooxidation, to afford 7b and 10.Finally, a 1,4-acyl migratin occurs in the benzyl derivative 4c, whereby the 1,4-diketone 12 is formed.