Dypnopinacol. Part IV. Tautomerism of α- and β-photodypnopinacol-ones (6-exo- and 6-endo-methyl-1,3,6-triphenylbicyclo[3,1,0]hex-2-en-2-yl phenyl ketone)

Abstract

α- and β-Photodypnopinacolones (6-exo- and 6-endo-methyl-1,3,6-triphenylbicyclo[3,1,0]hex-2-en-2-y phenyl ketone) are isomerised by bases to give 3-methyl-2,3,6-triphenylcyclohexa-1,5-dienyl phenyl ketone (δ-photodypnopinacolone). Mild base converts the α-isomer into r-3-methyl-2,3,t-6-triphenylcyclohexa-1,4-dienyl phenyl ketone (γ-photodypnopinacolone), which is converted by stronger base into the δ-isomer.