^{7, 24}-Cholestadien-3ß-ol, a Probable Intermediate in Cholesterol Synthesis

From the ¹ From the Departments of Medicine and Biochemistry, Medical School, University of Minnesota, Minneapolis, Minnesota 55455

A new sterol has been isolated from the skin of rats treated with triparanol. The structure proposed for this compound is ^{7, 24}-cholestadien-3ß-ol, on the basis of the following evidence.

1. The optical rotation is similar to that of ⁷-cholesten-3ß-ol.

2. Hydrogenation with Raney nickel catalyst yields a compound with chromatographic behavior similar to that of ⁷-cholesten-3ß-ol.

3. Hydrogenation with palladium catalyst yields a compound with an infrared spectrum indistinguishable from that of ⁸⁽¹⁴⁾-cholesten-3ß-ol. Approximately 1 mole of hydrogen is absorbed per mole of sterol.

4. The elemental composition is correct for the proposed structure.

5. The infrared spectrum is similar to that of ⁷-cholesten-3ß-ol, except for the differences to be expected from the presence of the ²⁴ bond.

6. The nuclear magnetic resonance spectrum differs from that of ⁷-cholesten-3ß-ol in the ways predicted.

^{7, 24}-Cholestadien-3ß-ol is biologically convertible to ⁷-cholesten-3ß-ol and to cholesterol. It can be derived from ^{8, 24}-cholestadien-3ß-ol, but the reverse reaction could not be shown.

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