Preparation and analgesic activity of (-)-11 alpha-substituted 1,2,3,4,5,6-hexahydro-6 alpha,7-(methyleneoxy)-2,6-methano-3-benzazocines.

Dihydrocodeinone oxime (1) under Beckmann rearrangement conditions gave a product (2) that facilitated the preparation of (-)-11 alpha-substituted 1,2,3,4,5,6-hexahydro-6 alpha,7-(methyleneoxy)-2,6-methano-3-benzazocines, a hitherto little-examined series of morphine partial structures. Compounds 7a and 12 gave good levels of agonist antinociceptive activity. Masking of the 8-oxygen function, as in 6 and 8, dramatically reduced mouse hot-plate activity, as did its loss (9).