Photodecarbonylation of 1,3-diphenylinden-2-one adducts; 1,5-sigmatropic shifts in sterically stabilised o-quinodimethanes
Abstract
Photodecarbonylation of the 1,3-diphenylinden-2-one–substituted maleimide adducts (II) and (VI) gave the sterically stabilised o-quinodimethanes (V; R1= R2= R3= Me) and (V; R1, R2=[CH2]4, R3= Me) in which 1,5-sigmatropic shift of the imido-group is preferred to alkyl migration.