potassium hydride in tetrahydrofuran; dimethyl sulfoxide T=20°C; 0.75 h;

1: methyl(diphenyl)phosphine oxide With n-butyllithium in tetrahydrofuran T=0°C; 0.25 h; 2: propionic acid methyl ester in tetrahydrofuran T=-78°C; 2.5 h; Further stages.;

n-butyllithium; sodium hydride in tetrahydrofuran 1.) 0 deg C, 15 min, 2.) -78 deg C, 5 min, 3.) warm to room temperature;

1: 58.1 percent / KH / tetrahydrofuran / 0.5 h / -30 °C 2: 5.4 percent / KH / tetrahydrofuran; dimethylsulfoxide / 0.75 h / 20 °C View Scheme

1: 75.5 percent / triethylamine / diethyl ether / 0 °C / 1. 0 deg C, 45 min 2. r.t., overnight 2: 58.1 percent / KH / tetrahydrofuran / 0.5 h / -30 °C 3: 5.4 percent / KH / tetrahydrofuran; dimethylsulfoxide / 0.75 h / 20 °C View Scheme