THE CHEMISTRY OF CHOLESTER1NE 99 



Recent observations show that oxycholestenone forms an ethyl 

 ester which speaks for the presence of hydroxyl, but that on 

 attempting to reduce either the ketone or the ester, instead of 

 the expected replacement of the tertiary hydroxyl by hydrogen, 1 

 two hydrogen atoms are added smoothly at the double link and 

 cholestandione is formed quantitatively. In the case of the 

 ester, therefore, reduction and saponification take place at the 

 same time, and the ester is also saponified merely by heating 

 with acetic acid. On account of these peculiarities, Windaus 

 concluded that oxycholestenone contains a keto-group which 

 functions in the enol form. This view is strengthened by the 

 close relationship in which it stands to cholestandione, for 

 whose formula there is other evidence. 



Oxycholestendiol, C2TH42O3, the third body produced by the 

 action of chromic acid, owing to its insolubility in benzene, is 

 easily separated from the others. The attack of the oxidiser in 

 this case seems to run on different lines, and to explain it we 

 have to assume the formation of the intermediate aldehyde body 

 shown in the scheme. Oxycholestendiol is saturated to bromine, 

 but it forms no hydrazone, so that direct experimental evidence 

 for the presence of the carbonyl group is lacking. Treated with 

 reagents like alcoholic potash, sulphuric or hydrochloric acids, 

 it loses water and passes to oxycholestenone. This change 

 takes place with the utmost readiness, and constitutes, perhaps, 

 the most characteristic property of the body. It necessitates 

 the existence of a hydroxyl group, though, on attempting to 

 acetylate this, loss of water occurs and oxycholestenone is again 

 produced. The formula given is therefore based chiefly upon 

 this obvious connection with oxycholestenone. 



The destructive effect of hot concentrated nitric acid on 

 cholesterine has already been mentioned. But in cold glacial 

 acetic acid solution cholesterine can be nitrated, a crystalline 

 substance, C2 7 H 4 2N 2 6 , which melts without decomposition at 

 128 , being obtained. This body, which has been called oxy- 

 nitrocholesteryl nitrate, is singularly stable towards most 

 chemical agents — acetyl oxide, phenyl lrydrazine, bromine, 

 alkalies, permanganate, and chromic acid being without effect. 

 That it is an ester of nitric acid was proved by preparing oxy- 

 nitrocholesteryl acetate from cholesteryl acetate, saponifying this 

 and combining the oxynitrocholesterine with nitric acid again ; 



1 Semmler, Ber. 37, 2520. 



