Of <//-coronaridine

The mercuric acetate dehydrogenation of carbomethoxydihydro-cleavacine (177) yields immonium salt 178, which undergoes transannular cyclization to give a mixture of coronaridine (180, R = Et, R, = H) and dihydrocantharanthine (180, R = H, Ri = Et). The reaction is accompanied... 

An enamine was obtained in the synthesis of coronaridine (648) by aluminum hydride reduction of a bridged lactam, followed by dehydration on alumina. Additional examples of enamine formation by reduction of enamides (649) and thioenamides (650) were reported. 

Another variant in the oxidation pattern of coronaridine is furnished by 5-hydroxy-6-oxocoronaridine (114, C21H24N204, MP 285-288°, [a]D +43.8°). The UV spectrum (kmax 218, 248, and 310 nm) exhibited the characteristic bathochromic shift of a 3-acylindole on addition of alkali. Diagnostically important fragment ions occurred at mlz 256(C14HioN04), 230 (C,3HI2N03), and 202 (C12H12N02) corresponding to structures 289, 290, and 291, respectively. The... 

Finally, two phenolic derivatives of coronaridine were isolated 10-hy-droxycoronaridine (98, C21H26N203) from the wood and stem bark of T. hey-neana (Ervatamia heyneana) (128) and 11-hydroxycoronaridine (99, amorphous, [a]D —34°) from T. attenuata (47). Both gave characteristic UV spectra with bathochromic shifts on addition of alkali, in agreement with the proposed... 

Both (159) and (161) were among the products obtained on oxidation of coronaridine by means of potassium permanganate. 

Domin contains voacangine, conopharyngine, and iboxygaine, E. obtusiuscula Mgf. contains coronaridine, isovoacangine, and a trace of epipandoline, while E. lifuana Boiteau has yielded pandine, pandoline, epipandoline, conopharyngine, and traces of coronaridine, and voacangine. 

At present, little can be said concerning the structure of villalstonine, except that it appears to be the first dimeric base in the Alstonia series. Its constituent chromophores are probably z-unsubstituted indole and dihydroindole nuclei these may be contained in tetra- and hexahydro-/3-carboline ring systems, but not even this can yet be regarded as established. The speculation that villalstonine may be regarded as composed of C19 and C21 units, the latter bearing the essential structural features of coronaridine (35), seems somewhat hasty on the basis of the published data. (See note added in proof, p. 201.)... 

The microbiological oxidation of coronaridine (229) by means of Sporotrichum sulfurescens affords a phenolic derivative (230) of uncertain orientation, together with a lactam (231) identical with an alkaloid previously isolated from Conopharyn-gia jollyana Stapf., and a hydroxylactam, provisionally formulated as (232). The action of Cunninghamella blakesleana Lendner leads to a hydroxycoronaridine, which is suspected to be (233). 

Compound 168 (CjiHjsNjOj) had a UV spectrum typical of an indole and the IR spectrum indicated the presence of methyl ester and NH/OH functions. The M peak was 18 mass units higher compared with coronaridine and fragments due to loss of 17 arid 31 mass units suggested the presence of a primary alcohol function. The NMR spectral data resembled that of coronaridine except for the H(3) signal which was shifted to lower field and the C(3) signal which was an oxymethylene (8 67.7). These observations are consistent with the proposed... 

Catharanthine-Ibogamine-Cleavamine Group. The chemistry and pharmacology of alkaloids of Tabernanthe iboga have been reviewed." New extractions have resulted in the isolation of coronaridine (previously observed), voacangine, isovoacangine, and ibogamine from the bark of Ervatamia coronaria, coronaridine and 19-oxocoronaridine from the roots of Tabernaemontana... 

Meyer WE, Coppola JA, Goldman L 1973 Alkaloid studies VIII Isolation and characterization of alkaloids of Tabernaemontana heyneana and antifertility properties of coronaridine. J Pharm Sci 62 1199-1201... 

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