Selective oxidative cleavage-cyclization of adamantane through the bridge carbon was developed in trifluoroperacetic acid (TFPAA). The methyl group in the bridge position was found to be the substituent that directs consecutive oxygen insertion into the cage structure during the course of a Criegee rearrangement. The formation of stable 5-methyl-4, 6- dioxabishomoadamant-5-yl cation at-25° C was observed. Stable carboxonium ion ...
