1: 85 percent / Na / xylene / 2 h / 100 °C 2: 70 percent / aq. CrO3; AcOH / 3 h / 15 °C View Scheme

1: isobutyric acid ethyl ester With n-butyllithium; diisopropylamine in diethyl ether T=-20 - 20°C; 1.75 h; Inert atmosphereSealed flask; 2: 1,2-di(p-toluene-sulfonyloxy)ethane in diethyl ether 24 h; Reflux;

1: isobutyric acid ethyl ester With n-butyllithium; diisopropylamine in diethyl ether T=-20 - 0°C; 1.5 h; Inert atmosphereSealed flask; 2: 1,2-bis(triflyloxy)ethane in diethyl ether T=20°C; 25 h; Reflux;

sulfuric acid Esterification; 16 h; Heating;