Photocyclization of 2-(2'-hydroxyphenyl) benzyl alcohol and derivatives via o-quinonemethide type intermediates

CG Huang, KA Beveridge, P Wan

Index: Huang; Beveridge, Kathryn Anne; Wan, Peter Journal of the American Chemical Society, 1991 , vol. 113, # 20 p. 7676 - 7684

Full Text: HTML

Citation Number: 48

Abstract

Abstract: A new photochemical reaction, the photocyclization of 2-(2'-hydroxyphenyl) benzyl alcohol (1) and derivatives to 6H-dibenzo [b, dlpyrans, is reported. The quantum yield for cyclization of 1 to give pyran 7 is 0.50 f 0.04 in aqueous solutions of pH> 10. At lower pH,@ is significantly lower. For example at pH 7,@= 0.25 0.03. Results from investigations of structure-reactivity, pH effects, and fluorescence data suggest a mechanism in which the ...