N-Methyl-N-2-propynyl-1-naphthalenecarboxamide, N-methyl-N-2-propynyl-
1-naphthaleneacetamide, and N-methyl-N-3-butynyl-1-naphthalenecarboxam
ide undergo intramolecular Diels-Alder reactions at 190-degrees, 250-d
egrees, and 270-degrees to give lactams 1, 6, and 9, respectively. The
cyclization temperatures are higher by 80-120-degrees as compared to
those of the corresponding anthracene derivatives. Elaboration of lact
am 6 gave the trans-4a-aryldecahydroisoquinoline derivative 7a which,
as the (-) isomer, was shown to have the same absolute stereochemistry
as morphine.