title: Cyanosilylation at pregnane side-chains. Selective synthesis and crystal structure of 20(R)-silylated cyanohydrins.
abstract: Trimethylsilylcyanide addition to different carbonyl moieties, i.e. saturated ketones, an enone and an aldehyde, at the steroid side-chain, was studied in the presence of a convenient catalyst. Depending on the nature of the carbonyl group, different outcomes were noticed. Saturated 20-keto pregnanes yielded epimerically pure silylated cyanohydrins, being the absolute configuration unambiguously established by X-ray crystallographic analysis.
authors.affiliation: Centro de Estudos Farmacêuticos, Lab. Química Farmacêutica, Faculdade de Farmácia, Universidade de Coimbra, Coimbra 3000, Portugal.
authors.forename: M Manuel
authors.initials: MM
authors.lastname: Cruz Silva
authors.forename: Lourdes C R
authors.initials: LC
authors.lastname: Andrade
authors.forename: José A
authors.initials: JA
authors.lastname: Paixão
authors.forename: M José
authors.initials: MJ
authors.lastname: de Almeida
authors.forename: M Luisa Sá
authors.initials: ML
authors.lastname: e Melo
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray / Q000379:methods; D003486:Cyanides / Q000737:chemistry*; D006868:Hydrolysis; D007659:Ketones; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry*; D011278:Pregnanes / Q000737:chemistry; D011487:Protein Conformation; D013237:Stereoisomerism; D013256:Steroids / Q000737:chemistry; D014965:X-Rays
chemical_list: D003486:Cyanides; D007659:Ketones; D009570:Nitriles; D011278:Pregnanes; D013256:Steroids; C430593:cyanohydrin