322 



IV. WAXES, HIGHER ALCOHOLS, ETC. 



considered by Windaiis and Wieland to offer a satisfactory explanation for 

 the difficulties inherent in the original formula. 



X, CH, 



c 



CHj .CH 



9 /9 \ 



HO 





C HC 



I el 



A B 



5 I 7 1 



xC. .CH2 



.CH 



H ?"' ^"s 



— C-CH-CHj-CHoCHpCH-CH, 



17 I 20 1Z 23 24 25 



.CH, 



C X 



H, H 



Cholesterol 



The small arabic numbers indicate the designations generally assigned to 

 the different carbon atoms in cholesterol, as well as in other sterols which 

 have a similar structure. A, B, C, and D are commonly used to designate 

 the rings, which may also be referred to as I, II, III, and IV, respectively. 



In addition to establishing the basic unit of the steroids as a phenanthrene 

 ring to which a five-carbon ring is attached, the new fomiula also involved 

 placing the side chain at Cn instead of at C19. According to Rosenheim 

 and King,^^°~^^- the length of the calciferol and ergosterol molecule deter- 

 mined experimentally by Bernal, ^^^ by the use of the x-ray diffraction pat- 

 terns, could not be reconciled with the original Wieland formula. More- 

 over, certain data on the surface films of sterols obtained by Adam and 

 Rosenheim^^^ were "nearly impossible to interpret" on this earlier basis. 

 The observation of Wieland and Dane^^® was also cited as strong proof that 

 the side chain on the sterols was attached to Cn. When the potential 

 intramolecular ring structure of cholic acid was closed, it was demonstrated 

 that the condensation product formed was methylcholanthrene. All of 



Methjlchohm throne 



1" J. D. Bernal, Nalure, 129, 277-278 (19:52). 



I'fi N. K. Adam and O. Rosenheim, Proc. Rn,/. Soc. London, A 126, 25-34 (1929). 



"6 H. Wieland and E. Dane, Z. physiol. Chem., 219, 240-244 (1933). 



