310 



Essays in Biochemistry 



tion an isomer of Diels' hydrocarbon, in all probability l'-methyl-l,2- 

 cyclopentanophenanthrene (Villa), and isorubijervine, 1,2-cyclopen- 

 tanophenanthrene (VIII6) itself. Furthermore, the presence of the 

 usual 3-hydroxy-5,6- double-bond grouping in both compounds could 

 be readily demonstrated by oxidation to the corresponding A 4 -unsatu- 

 rated ketones and reduction of the ketones to the Rosenheim-positive 

 allylic alcohols corresponding to allocholesterol. 



C..H 



CH 



HO 



CH. 



HO 



C,Hr 



CH, 



CH ( 



CH,CH ^N 

 OH 



IV 



VI 



VII 



Villa (R=CH, 

 VIII b (R=H) 



The last vestige of doubt regarding the significance of these results 

 vanished when it could be shown that both these alkamines were 

 indeed derivatives of solanidine (IX), which differed from this base 

 merely by the presence of a second hydroxy 1 group. With rubijervine 

 (X), the conversion to solanidine was effected by selective oxidation 

 of this group, for sound reasons assumed to occupy the 12 position 

 and to be a oriented, and Wolff-Kishner reduction of the resulting 

 12-monoketone. 3 In isorubijervine (XI) the additional hydroxyl group 

 is primary (formation of a monoketomonocarboxylic acid C27H41O3N 

 on oxidation of the 5,6-dihydro derivative 4 and resides on the methyl 

 carbon atom 18. This site was first deduced 4 from the absence of 



