Pyrolysis of (1-isobenzofuryl) methyl benzoate (9a), produced in situ from flash vacuum pyrolysis of (7-oxa-1-benzonorbornenyl) methyl benzoate (10a), gave methylenebenzocyclobutenone (4), 2-ethynylbenzaldehyde (5) and benzocyclopentadienone (6). The deuterium-labeled study indicated that the mechanism for the formation of these products involved the double migrations of benzoate group in 9a. ...
