The Veratrum Alkamines 



319 



of alkaloids differing in their skeletal structure clearly established, it 

 is legitimate to speculate on mechanisms by which the perhydrobenz- 

 fluorene system, observed here in nature for the first time, might arise 

 biogenetically from the normal steroid nucleus. The structures now 

 before us, as such, are not informative in this respect, except perhaps 

 insofar as it can be inferred from the relative prevalence of functional 

 groups, or of equivalent unsaturation, in the C/D ring moiety that this 

 portion of the molecule has lived through an eventful biogenetic past. 

 However, a significant clue (though it is one derived from purely 

 organic-chemical facts and hence, in the eyes of biogeneticists, perhaps 

 not too trustworthy) is available from the work of R. Hirschmann, 

 N. L. Wendler, and their colleagues on ring C/D rearrangements in 

 certain sapogenins appropriately substituted with oxygen in ring C. 25 



XXXVI Rockogenin 



CH, 



XXXVII 



XXXIX 



