Abstract α-Oxolactam enamines, namely, 3-piperidino-5, 6-dihydropyridin-2 (1 H)-one (1a) and 3-piperidino-1, 5, 6, 7-tetrahydroazepin-2-one (1b), were introduced for the first time into the Nenitzescu reaction. The processes yield cyclic adducts 3a—e, 6. On heating in acetic acid, they are transformed into benzofuropyridone 7 and benzofuroazepinones 10a, d, and 12 and, unexpectedly, into chromenopyrrole 8 and chromenopyridines 9a—d and 11.
[Lyubchanskaya, Valeria M.; Alekseeva, Lyudmila M.; Savina, Svetlana A.; Shashkov, Alexander S.; Granik, Vladimir G. Mendeleev Communications, 2002 , vol. 12, # 1 p. 15 - 17]
