Rubremetinium bromide

The photolytic and thermolytic decomposition of emetine have been studied. Photolysis has been shown to involve oxidation and fragmentation, whilst thermolysis involves only oxidation. Compounds identified were emetamine, O-methylpsychotrine, l, 2 -didehydroemetine, tetradehydroemetinium bromide, rubremetinium bromide, 6,7-dimethoxy-3,4-dihydroisoquinoline, 6,7-dimethoxy-l-methyl-3,4-dihydroisoquinoline, 3-ethyl-9,10-dimethoxy-l,4-dihydrobenzo[a]quinolizinium chloride, its 2-methyl-derivative, and the dimerized compound (112).141... 

The structure of the (+)-rubremetinium cation (129) 119-123), the mild oxidation product from emetine (1) 1,121) or O-methylpsychotrine (7) 1,86), and those of its hydrogenation products, (—)-A(or a)-dihydroru-bremetine (131) 120,121,124-126), (+)-B(or / )-dihydrorubremetine (132) 120,121,124-126), and (+)-tetrahydrodehydroemetine (133) 121,124, 126), have been inferred from the early studies summarized in Chapter 3 of Volume XIII and elsewhere 4,5). In early synthetic studies of ( )-emetine (1) and ( )-0-methylpsychotrine (7), ( )-rubremetinium bromide (129 -Br) 41,54,55,57) and iodide (129-1-) 51,52) were prepared by dehydrogenation of synthetic alkaloids of mixed or unknown stereochemistry in order to compare with the natural materials. On the basis of structure... 

Tetradehydroemetine (acid oxalate) (38) Dehydroemetiniumbromide (33) Dehydro-O-methylpsychotrine (bromide) (33) Dehydroemetamine (bromide) (33) d(-Rubremetinium bromide, synthetic (52) a-Dihydrorubremetine (102) i8-Dihydrorubremetine (102) 0-Methylpsychotrine hydrogen oxalate (103) 358 14.70... 

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