pyridinium chlorochromate in dichloromethane 2 h; Ambient temperature;

1: TsOH, CH(OEt)3 / benzene / 1.5 h / 72 °C 2: 92.1 percent / PCC / CH2Cl2 / 2 h / Ambient temperature View Scheme

sodium acetate; toluene-4-sulfonic acid; pyridinium chlorochromate 1.) benzene, reflux, 43 h, 2.) CH2Cl2, RT, 5.5 h; Yield given. Multistep reaction;

1: acetylene With potassium tert-butylate in tetrahydrofuran T=0 - 20°C; 2 h; 2: 7α-methyl-3,3-(ethylenedioxy)-5(10)-estren-17-one; acetylene in tetrahydrofuran T=4 - 8°C; 4 h; 3: With ammonium chloride in water; toluene T=0 - 20°C; 1.75 h;