Tandem acylation - Cycloalkylation with cyclohexene 1-acetic acid: A new entry to aporphine alkaloids

Article abstract of DOI:10.1016/0040-4039(96)00104-9

Tandem acylation-cycloalkylation of 3,4-dimethoxy phenylethylamine (1) with cyclohexene-1-acetic acid (2) in polyphosphoric acid (PPA) afforded 8-(2-aminoethyl)-1,2,3,4,4a,10a-hexahydro-9-oxo-phenanthrene (3) which on cyclisation followed by dehydrogenation with Pd-C afforded dehydronornuciferine (5). Hydrogenation of 5 yielded (±) N-nornuciferine (6).