The synthesis of cholesterol-2,2,4,4,6-d5

Article abstract of DOI:10.1002/jlcr.2580160316

Cholesterol-3,4-d₂ and -2,2,4,4,6-d₅ have been synthesized from Δ⁴-cholestene-3-one for use as mass spectrometric stable isotope internal standards. Conversion of Δ⁴-cholesten-3-one to the enol acetate followed by reduction with sodium borodeuteride in a deuterated solvent yielded cholesterol-3,4-d₂. Similarly Δ⁴-cholesten-3-one-2,2,4,6,6-d₅ obtained by base-catalyzed exchange of Δ⁴-cholesten-3-one in ethanol-0-d₁ was converted to the enol acetate, followed by reduction with sodium borohydride in a deuterated medium to give cholesterol-2,2,4,4,6-d₅.