AM1 STUDIES OF PHOTOCHEMICAL-REACTIONS OCCURRING FROM THE S-1 AND THET-1 STATES OF SOME CYCLOPROPYL KETONES

AMI studies of photochemical reaction mechanisms are carried out for t hree cyclopropyl ketones, namely methyl cyclopropyl ketone, 1-cyclopro pyl-2-propanone and 1-cyclopropyl-3-butanone. Transition states for th e feasible reactions have been verified by carrying out normal coordin ate analysis and the activation barriers for the reactions have been c alculated. The cyclopropane fission reaction is found to be more favou rable energetically in comparison to the alpha-cleavage reactions for methyl cyclopropyl ketone. However, for 1-cyclopropyl-2-propanone and 1-cyclopropyl-3-butanone, the alpha-cleavage reaction is preferred ove r other competing reactions. (C) 1998 Elsevier Science B.V. All rights reserved.