Hetero-Diels-Alder reactions opposing enamines (dihydroquinoline and d
ihydroisoquinoline derivatives) to substituted nitrosoalkenes are desc
ribed. The stereoselectivity and regiospecificity of the reactions are
discussed. New fused oxazinotetrahydroquinoline and oxazinotetrahydro
isoquinoline structures are reported. (C) 1997 Elsevier Science Ltd. A
ll rights reserved.