J‘-Cholestenone

A 250-mI round-bottom flask fitted with a condenser (drying tube) is charged with a mixture of 2-bromocholestanone (4.7 g, 0.01 mole), lithium carbonate (7.4 g, 0.10 mole), and 100 ml of dimethylformamide. The system is flushed with nitrogen and then refluxed (mantle) for 18-24 hours. After the reflux period, the solution is cooled and poured into 500 ml of water. The aqueous mixture is extracted with 50 ml of ether, the ether extract is dried (sodium sulfate), and the ether is removed (rotary evaporator). The residue may be recrystallized from ethanol or methanol. J -Cholestenone is a white solid, mp 98-100°. 

The relationship of cholesterol to cholestanol has now been delineated. Early experiments of Schoenheimer ef al. (103, 104) and Rosenfeld and Webster (105) resulted in a proposal that cholesterol was metabolized to -cholestenone (XXIX), which was reduced to cholestanol or coprostanol (106) indeed. Baker and Greenberg (106) detected C-cholestanol in rat feces after administration of radioactive acetate. Anker and Bloch (107) and Stokes et al. (108) found efficient conversion of labeled J -cholestenone to tissue cholestanol in rats. Cholesterol was shown (109) to be a precursor of cholestanol in the adrenals, liver, and intestine of guinea pigs. With cholesterol-4- - C-4/3- H Werbin et al. showed that the cholestanol isolated from the adrenals contained as much as 14% of the tritium at positions 5 and 6, whereas the cholestanol obtained from liver and intestine was virtually devoid of tritium at these positions (110). Based on these observations they proposed the following possible pathway ... 

Harold et al. (114) also showed that the acidic biliary metabolites derived from J -cholestenone-C in the bile fistula rat appeared in fractions associated with trihydroxy and dihydroxy bile acids. Recrystallization with carrier cholic acid virtually eliminated the metabolite from this acid. By similar technique the C-metabolite in the dihydroxy fractions was shown to differ from deoxycholic and chenodeoxycholic acids however, in the latter case conversion to the diacetate was necessary to remove the C. 

Fig. 4. Oraph Olustfuting Uie dependence of capacity ratios on the composition of eluents containing n-heptane and dichloromethane. The stationary phase is LiChrosorb SI 100 silica gel. Sample A, ethyl benzene B. anthracene C, m-terphenyl D, nitrobenzene F. benzonitrile F, benzophenone O, acetophenone H, l,4..Vxylenol I, r>-nitroaniline J, m nitioaniline K, A -cholestenone L, p-nitroaniline.

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