Elimination of the 4-hydroxyl group of the alkaloids related to morphine—II

Dihydrothebaine-φ, dihydrothebainone-Δ⁵-enol methylether and dihydrothebainone were converted to the respective 4-phenylethers by Ullmann reaction in good yields. These phenylether derivatives were reduced to 4-desoxy compounds by sodium-liquid ammonia reduction.

Clemmensen reduction of the phenylether and the desoxy derivatives gave (-)-3-methoxy-4-phenoxy-N-methyl-morphinan and (-)-3-methoxy-N-methylmorphinan respectively.