cyclopentenyl) ethanal, 19* 20 formally through a selective abstraction of the syn-7-H from diradical 4 in preference to the endo-6-H. Carvonecamphor is photoisomerized in methanol to an aldoketene intermediate which in turn is converted into the corresponding ester. Only the a-exo-H is abstracted intramolecularly as the ketene forms. 21 Photolysis of bicyclo [5.2. lldecan-10-one in pentane gives products derived from octamethyleneketene but no ...
