ARYLCYCLOPROPANE PHOTOCHEMISTRY. UNUSUAL AROMATIC SUBSTITUENT EFFECTS ON THE PHOTOCHEMICAL REARRANGEMENT OF (2-ARYLCYCLOPROPYL)METHYL ACETATES TO 1-ARYLHOMOALLYL ACETATES.

Article abstract of DOI:10.1021/ja00219a040

Irradiation of trans(2-arylcyclopropyl)methyl acetates a 4-butenyl-1-arylacetate (7a,b,d-h) via an ionic mechanism from the singlet state. Similar rearrangements occurred with exo-(1,1a,6,6a-tetrahydrocycloprop left bracket a right bracket inden-1-yl)methyl acetate and the 4-cyano derivative. Excited state reaction rate constants were determined from reactant fluorescence lifetimes and product quantum yields. It is concluded that the rate-determining step involves conversion of the initially formed aromatic excited state to a reactive cyclopropane excited state and that cyclopropane to aromatic ring charge transfer enhances this process.