title: Studies of the synthesis of biomarkers. XI. Synthesis of 4,5-secocholestane and 4-methyl-4,5-secocholestane.
abstract: 4,5-Secocholestane (1a) and 4-methyl-4,5-secocholestane (1b) were synthesized from cholesterol (2) in five and seven steps, respectively. The key intermediate, 5-oxo-4,5-secocholestan-4-al (7) was reduced by the Clemmensen method to afford 1a. Meanwhile, 7 underwent selective Wittig reaction, Clemmensen reduction, and hydrogenation to give another target molecule, 1b. The structure of an unknown biomarker was shown to be different from the proposed 1a by gas chromatographic and mass spectrometric comparison.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Lanzhou University, People's Republic of China.
authors.forename: J G
authors.initials: JG
authors.lastname: Ma
authors.forename: T S
authors.initials: TS
authors.lastname: Li
authors.forename: Y L
authors.initials: YL
authors.lastname: Li
mesh_terms: D002776:Cholestanes / Q000138:chemical synthesis* / Q000737:chemistry; D002784:Cholesterol / Q000737:chemistry*; D002849:Chromatography, Gas; D006868:Hydrolysis; D006900:Hydroxylation; D013058:Mass Spectrometry; D015394:Molecular Structure; D012632:Secosteroids / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D002776:Cholestanes; D012632:Secosteroids; C078294:4-methyl-4,5-secocholestane; C078293:4,5-secocholestane; D002784:Cholesterol