2-Benzalcyclopentanone oxide, 2-beuzalcyclohexanone oxide and 2- benzalcycloheptanone oxide have been isonicrizcti to 2-phenyl-l, 3-cyclohexanedione, 2- phenyl-1, 3-cycloheptanedione and 2-phenyl-1, 3-cyclooctanedione, respectively, by treatment with boron trifluoride etherate in benzene solution. When the same cyclohexanone and cycloheptanone derivatives were treated with boron trifluoride in ether solution, the ...