We describe the application of a novel ene-like reaction developed in our laboratory to the facile preparation of benzazocinone and benzazocenone intermediates of the type 3. Thus, ene-like reaction of 1 with 2-methoxypropene furnished adduct 2. This material underwent tandem intramolecular 1,3-dipolar azide cycloaddition and photolysis of the resulting triazoline to give 3. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE MAI) The newly developed avenue to these medium-ring heterocycles should be useful in a total synthesis of the antitumor agent, FR900482, 4. A synthesis of the highly substituted aldehyde 6, which could produce intermediates 5 suitable for the ultimate elaboration into 4 by the new chemistry, has also been developed.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE MAI)