title: Novel stereoselective synthesis of 7beta-methyl-substituted 5-androstene derivatives.
abstract: The 7beta-methyl-5-androstene derivatives 11a-c were prepared in good yield with high stereoselectivities starting from 3beta-acetoxyandrost-5-en-17-one 4. The addition of methylmagnesium iodide to the 7-carbonyl group of 7a-c gave, after hydrolysis, two isomers 9a-c and 10a-c, which were stereoselectively deoxygenated by means of an ionic hydrogenation to afford the compounds 11a-c.
authors.affiliation: Institute of Materia Medica, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 294 Taiyuan Road, Shanghai 200031, PR China.
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Zheng
authors.forename: Yuanchao
authors.initials: Y
authors.lastname: Li
mesh_terms: D000736:Androstenes / Q000138:chemical synthesis*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D006868:Hydrolysis; D008745:Methylation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D014961:X-Ray Diffraction
chemical_list: D000736:Androstenes