INTRAMOLECULAR DIELS-ALDER REACTIONS .4. ADDITIONS TO NAPHTHALENE

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.