19-iodocholesterol and 19-iodocholesterol-3-acetate

Since 19-iodocholesterol ethyl and methyl ethers and 3 beta-iodo-5-cholestene localized in dog adrenal, the distribution of 19-iodocholesterol 3-acetate was similarly studied. This ester was concentrated by the dog adrenal to the same extent as 19-iodocholesterol. Despite a previous report that the ester was not appreciably taken up by the rat adrenals, distribution experiments were undertaken, and the results showed that the ester preferentially localized in the adrenals of the rat as well as the dog.

Topics: 19-Iodocholesterol; Adrenal Glands; Animals; Cholesterol; Dogs; Rats; Rats, Inbred Strains; Species Specificity; Tissue Distribution

19-Iodocholesterol 3-acetate (VI) was synthesized in a single step by iodo group substitution for hydroxyl using either one of two different reagents: (1) carbodiimidonium methiodide (VIII) or (2) triphenyl-phosphine/N-iodosuccinimide (IX). The yields were as satisfactory as those obtained from the two step iodide replacement of a 19-hydroxy group via the 19-tosyloxy group. The principal intermediate, 19-hydroxy cholesterol 3-acetate (V), was derived in appreciable quantities, and relatively inexpensively, through the Pb (OCOCH3) 4 photolytic oxidation of the bromohydrin of cholesterol 3-acetate (III) to the epoxide (IV) thence Zn reduction to the 19-hydroxy compound. A specially designed 12 liter flask was of aid in accomplishing the photolysis reaction. Dry column chromatography with the supportive puncture sampling was integral to achieving the good yields and high purity of 19-iodocholesterol (VIII).

Topics: 19-Iodocholesterol; Cholesterol Esters; Iodine Radioisotopes; Isotope Labeling