Dehydrierende kondensation quartärer benzyl-tetrahydro-isochinoline

The Aporphine Alkaloids

“…220-222°d ec., [«]14d -116.9°( MeOH), which was found to be identical (infrared spectra and Rt values) with synthetic racemic laureline methiodide. 33. Xylopine (XL) Ci8H1703N M.p.…”

“…Lately, a study of the mass spectra of these compounds has also been carried out (95). An aporphine-benzylisoquinoline dimer, thalicarpine, has been characterized by Kupchan (84), and finally the first synthesis of an aporphine base through phenolic oxidative coupling has been reported by Franck, a transformation which emulates the biosynthetic process of nature (33). All of these topics will be discussed in the present review.…”

Oxidative Condensation of Quaternary Phenolic Bases

“…The quaternary coclaurine (24), which occurs in various kinds of magnolia as magnocurarine, is accessible in large quantities by nine conventional synthetic steps, starting from vanillin. Its oxidation with potassium ferricyanide gave a crystalline dehydrogenation product, m.p.…”

“…Its oxidation with potassium ferricyanide gave a crystalline dehydrogenation product, m.p. 225 "C [24]. We shall now proceed to consider various possibilities for its structure.…”

“…Therefore, oxidation occurs exclusively at the free hydroxyl group of the isoquinoline residue. Thus the oxidation products of (24) and (25) can contain only one bond between the isoquinoline residues and should both yield an identical pentamethyl ether. This was indeed the case.…”