Acronycine dimers and trimers

An interesting development in the chemistry of this alkaloid is the discovery that when acronycine is demethylated with methanolic hydrochloric acid the product noracronycine reacts further to give dimers (51) and (52), a trimer (53) and oligomers (S. Funayama and G.A. Cordell, Planta Med., 1983, 48, 253 J.org.Chem., 1985, 50, 1737). 

Related to these structures is the natural dimer glycobismine A (54) first isolated from Glycosmis citrifolia by H. Furukawa et al., (Chem.pharm.Bull., 1984, 32, 1647). 

Developments in the chemistry of the alkaloids of this group have been annually reviewed in Specialist Periodical Reports of the Royal Society of Chemistry The Alkaloids Vols. 7 (1975-6), 8 (1976-7), 9 (1977-8), 10 (1978-9), 11 (1979-80), 12 (1980-1) and 13 (1981-2) and subsequently in Natural Product Reports 1984, 355 (1982-3), 1985, 2, 81 (1983-4) 

The range of simple isoquinoline alkaloids, principally obtained from cacti, has recently been greatly expanded by the isolation of isoquinolines, 3,4-dihydroisoquinolines and 1,2,3,4-tetrahydroisoquinolines bearing one, two, three and 

Isocorypal1ine (4, R =H, R =Me) has been oxidised by lead (IV) -acetate to the quinone acetal (5) which suffers Thiele acetylation to a product that may be hydrolysed and O-methylated to tehuanine (H. Hara et al.. Heterocycles, 1982, ]] (Special Issue), 293. Corypalline (4, R =Me, R =H) with lead tetra- 

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See also in sourсe #XX -- [ ]

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