2201. Cholesterol

Nomenclature

CAS number: 57-88-5
(3β)-Cholest-5-en-3-ol; cholesterin.
C27H46O; mol wt 386.65.
C 83.87%, H 11.99%, O 4.14%.

Description and references

Principal sterol of the higher animals. Found in all body tissues, esp in the brain, spinal cord, and in animal fats or oils. Main constituent of gallstones. Prepd commercially from the spinal cord of cattle by petr ether extraction of the nonsaponifiable matter. Also produced from wool grease. Cholesterol from animal organs always contains cholestanol (dihydrocholesterol) and other satd sterols. Purification by repeated bromination: Schoenheimer, J. Biol. Chem. 105, 355 (1934); Fieser, Org. Synth. coll. vol. IV, 195 (1963). Laboratory procedure for isoln from gallstones: L. F. Fieser, Organic Experiments (Heath, Boston, 3rd ed., 1964) p 70. Total synthesis: Keana, Johnson, Steroids 4, 457 (1964). Reviews and bibliographies: Fieser, Fieser, Steroids (Reinhold, New York, Chapman & Hall, London, 1959); Lettré et al., Ueber Sterine, Gallens"auren und verwandte Naturstoffe (Stuttgart, 2nd ed., 1955); R. P. Cook, Cholesterol (Chemistry, Biochemistry and Pathology) (Academic Press, New York, 1958) 542 pp; J. T. Gwynne, J. F. Strauss, Endocr. Rev. 3, 299-329 (1982).

Chemical structure

Properties

Monohydrate, pearly leaflets or plates from dil alcohol. Becomes anhydr at 70-80°. When anhydr mp 148.5°. Has been sublimed as orthorhombic needles. bp0.5 233°; bp760 360° (some decompn). d 1.03 (monohydrate); d1919 1.052 (anhydr). [α]D20 -31.5° (c = 2 in ether); [α]D20 -39.5° (c = 2 in chloroform). Absorption spectrum: Heilbron et al., J. Chem. Soc. 1928, 47. Practically insol in water (about 0.2 mg/100 ml H2O). Slightly sol in alc (1.29% w/w at 20°), more sol in hot alc (100 g of satd 96% alcoholic soln contains 28 g at 80°). One gram dissolves in 2.8 ml ether, in 4.5 ml chloroform, in 1.5 ml pyridine. Also sol in benzene, petr ether, oils, fats. Soly in aq solns of bile salts: Rosin, Z. Physiol. Chem. 124, 282 (1923). Solubilization: Gemant, Life Sci. 1, 233 (June 1962). Is pptd by digitonin. Gives intense red color with rosaniline in chloroform soln.

Derivative

Methyl ether.
C28H48O; mol wt 400.68.
C 83.93%, H 12.07%, O 3.99%.

Properties

Crystals from acetone, mp 84°. [α]D20 -45.8° (c = 1.2 in chloroform).

Derivative

Acetate.
C29H48O2; mol wt 428.69.
C 81.25%, H 11.29%, O 7.46%.

Properties

Needles from acetone, mp 115-116°. [α]D20 -47.4° (c = 2 in chloroform).

Derivative

Benzoate.
C34H50O2; mol wt 490.76.
C 83.21%, H 10.27%, O 6.52%.

Properties

mp 145.5° (the melt becomes clear at 180°). [α]D25 -13.7° (c = 0.9 in chloroform).

Use

Pharmaceutic aid (emulsifying agent).