Araliopsis soyauxii

The hydroxydihydropyranoquinolone (—)-ribalinine (47) is a constituent of the trunk and root bark of Araliopsis soyauxii f the (+ )-enantiomer (folifine) was obtained earlier from Haplophyllum species and the racemate, which has been synthesized was isolated from B. riedelianum. (-l-)-Isoplatydesmine (43) has also been isolated from A. soyauxii and can be regarded as a new alkaloid since isoplatydesmine obtained recently from Pelea barbigera (cf. Vol. 6) probably is the... 

Araliopsine (62), which is present in Araliopsis soyauxii (J. Vaquette et al., Phytochem., 1975, 15, 743) and Zanthoxyllum simulans (z. Chang et al., Yaoxuc Xuebao, 1981, 16, 394 C.A., 1982, 97, 20735) has been synthesised by G.M. Coppola (J. heterocyclic Chem.,1983, 1589) by reacting N-methylisatoic anhydride with the lithium enolate (51) and treatment of the intermediate epoxide with acid. 

When heated briefly above its melting point, (+)-N-methyl-platydesminium iodide gave the 4-quinolone 52, [a]D + 82° (MeOH) (37), identified by comparison with the synthetic racemate (27). Higa and Scheuer (43) have now isolated from Pelea barbigera (Gray) Hillebrand quinolone 52, named isoplatydesmine. Araliopsis soyauxii has been shown to contain (+)-isoplatydesmine as the major alkaloid of the root bark (44) the same enantiomer is a constituent of A. tabouensis (45). 

Araliopsis soyauxii (Section III,C,3) thus has the (R) configuration, assuming that the rearrangement reaction follows the same stereochemical pathway as the balfourodine-(//-balfourodine transformation. 

Ribalinine n 3 -OH, 1-Me Araliopsis soyauxii [44], Euodia gracilis [23], Haplophyllum patavinum [36], Skimmia laureola [69], Teclea nobilis [22], Zanihoxylum mayu Eagara mayu) [44]... 

The anellation of the three-ring system is generally linear, such as in dictamnine (7, R = Me), but a few representatives with angular anellation have been found, e.g., 2, 3 -dihydrofuroquinolin-2-one araliopsine (9, N-Me) isolated from Araliopsis soyauxii [44], However, angular furoquinoline alkaloids are not known. 

The same enantiomer occurs in Araliopsis tabouensis Aubrev et Pellegr. (45), and (—)-ribalinine has been found in the root bark of A. soyauxii Engl. (44). 

Veprisine ni 7,8-diOMe, 1-Me Araliopsis tabouensis (A. soyauxii) [23], Glycosmis mauritiana [43], Oricia renieri [44], Stauranthus perforatus [35], Vepris louisii [44], V. stolzii [44]... 

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