Z-Vomilenine

The writers suggest that raucaffriline, whose structure has not been conclusively determined (88a), may in fact be identical with Z-vomilenine (33). 

Scheme 11. Transformation of Z-vomilenine (33), via intermediate 33a/33b chano form), to perakine (31).

Takayama et ci. (167b) have shown that bodi synthetic f vomilenine (32) and synthetic Z-vomilenine (33) are transformed to perakine (31), but the latter is transformed much faster and under less drastic conditions. This supports the assumption that perakine (31) is "directly" formed from Z-vomilenine (33) (vide supra), which is more or less totally "consumed" during the isolation procedure and which is thus difficult to detect as a naturally occurring alkaloid. 

FALKENHAGEN, H., STOCKIGT, J., Enzymatic biosynthesis of vomilenine, a key intermediate of the ajmaline pathway, catalyzed by a novel cytochrome P450-dependent enzyme from plant cell cultures of Rauwoljia serpentina. Z. Naturforsch., 1995, 50C, 45-53. 

A similar procedure starting from majorinine (10-methoxy- -vomilenine) (46) can be expected to lead, also via its Z-isomer, to 10-methoxyperakine (45) and then, after reduction and acetylation [10% acetic acid was used in the applied extraction procedure (ff5)], to vincawajine (57) J67d). 

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