A representative procedure for the intramolecular Diels-Alder reaction of o-quinone methide N-alkenylimine intermediate (6) is exemplified by the synthesis of benzo [c] quinolizidine (7b). To a refluxing suspension of 304 mg (2 mmol) of CsF in 10 mL of acetonitrile, a solution of 400 mg (1 mmol) of [o-[(trimethylsilyl) hex-5-enylamino] benzyl] trimethylammonium bromide (9)'in 10 mL of acetonitrile was added dropwise over 1 h and then heated at ...
