THE CHEMISTRY OF CHOLESTERINE 103 



skill, are best followed with the following formulae taken from 

 their original paper (1904) : 



CH 2 v /CO CH, \ /CO 



I. I >C a H a <r I -> II. I >C a H«< I 



CHOH/ \CH 3 CH.CK \CH 2 



Cholestanonol m.p. 142 /3 Chlorcholestanone m.p. 180° 



CH CH. 2 



L -2 



/ 



Acid CtfHtt&O^ m.p. 243° Acid C, 7 H 44 5 m.p. 239 



— > III. /C3H38V — > IV. /C a Hsgr 



CH.CK \COOH CHOH/ \COOH 



CH,\ /COOH COOHv /COOH 



2 V /LUUH IUUH\ /K 



/C^^gs. — > VI. /CgjH^ 



CO / \COOH COOH/ \COOH 



Acid Co7H 42 5 m.p. 25 5 Acid C, 7 H 43 8 m.p. 174° 



The hydroxyl of (I.) was replaced by chlorine through the 

 action of phosphorus pentachloride, and was thus "protected" 

 from the oxidising agent employed — viz. nitric acid in glacial 

 acetic acid solution. The acid (III.), C27H43CIO4, is obviously 

 formed by the opening of the CO . CH 2 group of cholestanonol. 

 The chlorine was now replaced by hydroxyl, giving the oxy- 

 acid (IV.), which was converted by dilute chromic acid mixture 

 to the keto-acid (V.). This forms an oxime melting at 213 . 

 (V.), treated with strong chromic acid, gave the tetrabasic acid 

 (VI.). In this way two of the rings of the original cholestanonol 

 were opened, and it is possible that the results may be of the 

 greatest value in clearing up the constitution of cholesterine. 



COPROSTERINE 



As cholesterine is so widely and abundantly diffused 

 throughout the organs and tissues, it becomes of interest to 

 discover whether it appears among the waste products of the 

 human body. Bondzynski and Humnicki, in 1896, showed that 

 it was present in the faeces as a hydrogenated derivative, to 

 which they assigned the formula C ?7 H 48 0. This coprosterine, 

 as it was called, is excreted at the rate of about f of a gramme 

 per day. So far as it has been examined it functions as a 

 secondary alcohol, though, unlike cholesterine, it is saturated 

 to bromine. It crystallises from alcohol in masses of fine 

 needles melting at 99-100 C, has a rotation [a D ] of + 24 , and 

 forms crystalline acetyl, benzoyl, cinnamoyl, etc., derivatives. 



Bondzynski and Humnicki regard coprosterine as a dihydro- 



