Dypnopinacol. Part III. The photochemistry of 4-methyl-2,4,6-triphenylcyclohexa-2,6-dienyl phenyl ketone (isodypnopinacolone)

Abstract

The two products of photorearrangement of 4-methyl-2,4,6-triphenylcyclohexa-2,6-dienyl phenyl ketone (isodypnopinacolone), first noted by Delacre in 1896, are now shown to be characteristic of cyclohexa-1,3-diene photo-transformations. Degradative reactions of the major product have shown it to be 6-exo-methyl-1,3,6-tri-phenylbicyclo[3,1,0]hex-2-en-2-yl phenyl ketone (α-photodypnopinacolone). The minor product is the 6-endo-methyl isomer (β-photodypnopinacolone).