title: Studies of the synthesis of biomarkers. VII. Synthesis of 5 alpha-(17R,20R)-14,15-secocholestane.
abstract: 5 alpha-(17R,20R)-14,15-Secocholestane (12) was synthesized from cholesterol (1) in 12 steps. The key intermediate, 5 alpha-cholest-14-en-3 beta-yl acetate (4), underwent ozonization, reduction, hydrolysis, and oxidation to provide 5 alpha-14,15-secocholesta-3,14,15-trione (8). One of the Clemmensen reduction products of 8 is 5 alpha(17R,20R)-14,15-secocholest-15-ol (11); treatment of the alcohol (11) with tosyl chloride and subsequent reduction with lithium aluminum hydride yielded the target molecule (12).
authors.affiliation: Laboratory of Applied Organic Chemistry, Lanzhou University, People's Republic of China.
authors.forename: T S
authors.initials: TS
authors.lastname: Li
authors.forename: Y L
authors.initials: YL
authors.lastname: Li
authors.forename: X T
authors.initials: XT
authors.lastname: Liang
mesh_terms: D000535:Aluminum; D017607:Aluminum Compounds; D055598:Chemical Phenomena; D002621:Chemistry; D002776:Cholestanes / Q000138:chemical synthesis*; D002784:Cholesterol; D006868:Hydrolysis; D008094:Lithium; D018020:Lithium Compounds; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010126:Ozone; D012632:Secosteroids / Q000138:chemical synthesis*; D014105:Tosyl Compounds
chemical_list: D017607:Aluminum Compounds; D002776:Cholestanes; D018020:Lithium Compounds; D012632:Secosteroids; D014105:Tosyl Compounds; C025506:4-toluenesulfonyl chloride; C065252:14,15-secocholestane; D010126:Ozone; C042073:lithium aluminum hydride; D002784:Cholesterol; D008094:Lithium; D000535:Aluminum