AN ALTERNATIVE TOTAL SYNTHESIS OF N-METHYLCAAVERINE THROUGH PHENOLIC OXIDATION

Phenolic oxidation of 1,2,3,4-tetrahydro-7-hydroxy-1-(2-hydroxybenzyl)-6- methoxy-2-methylisoquinoline (Ib) afforded the dienone (IIb) in 2.4% yield, the dimeric benzylisoquinoline (XIa) in 1.1% yield, and an unknown carbonyl compound. Borohydride reduction of the dienone (IIb) gave the corresponding dienol (XVII), whose rearrangement in acidic media gave the 1-hydroxy-2- methoxyaporphine (XVIII). This aporphine was identical with (±)-N- methylcaaverine (XVIII), which was derived from the (±)-caaverine (XIX) by Eschweiler - Clarke reaction.