Studies of the synthesis of biomarkers. VII. Synthesis of 5α-(17R,20R)-14,15-secocholestane

Article abstract of DOI:10.1016/0039-128X(90)90042-A

5α-(17R,20R)-14,15-Secocholestane (12) was synthesized from cholesterol (1) in 12 steps.The key intermediate, 5α-cholest-14-en-3β-yl acetate (4), underwent ozonization, reduction, hydrolysis, and oxidation to provide 5α-14,15-secocholesta-3,14,15-trione (8).One of the Clemmensen reduction products of 8 is 5α(17R,20R)-14,15-secocholest-15-ol (II), treatment of the alcohol (II) with tosyl chloride and subsequent reduction with lithium aluminum hydride yielded the target molecule (12).