title: Steroid total synthesis. IX. Alternative routes to (+ -)- and (+)-estr-4-ene-3,17-dione and (+ -)-13 beta-13 -ethylgon-4-ene-3,17-dione via novel nitrile intermediates.
mesh_terms: D004962:Estranes / Q000138:chemical synthesis*; D007664:Ketosteroids / Q000138:chemical synthesis; D007783:Lactones; D008722:Methods; D009570:Nitriles; D009654:Norsteroids / Q000138:chemical synthesis
chemical_list: D004962:Estranes; D007664:Ketosteroids; D007783:Lactones; D009570:Nitriles; D009654:Norsteroids