Novel analgesics and molecular rearrangements in the morphine–thebaine group. Part IX. A novel aromatisation during Hofmann degradation
Abstract
Hofmann degradation of the methohydroxide of the thebainone-derived methine base (2) affords an optically active neutral product, (–)-1,2-dimethoxy-7-(4-hydroxy-2-isopropylphenyl)-8-vinylnaphthalene (12). At higher temperatures the racemate and its methyl ether are obtained. Structures were assigned to these products after consideration of their n.m.r. spectra. The mechanism of the rearrangement is discussed.