lithium diisopropyl amide in tetrahydrofuran T=-80 - 20°C; 10 h;

1.1: BuLi / diethyl ether; hexane / 0.5 h / -25 °C 1.2: 73 percent / diethyl ether; hexane / -80 - 20 °C 2.1: 76 percent / 3-chloroperbenzoic acid / CH2Cl2 / 5 - 10 °C 3.1: 68 percent / LDA / tetrahydrofuran / 10 h / -80 - 20 °C View Scheme

1: 76 percent / 3-chloroperbenzoic acid / CH2Cl2 / 5 - 10 °C 2: 68 percent / LDA / tetrahydrofuran / 10 h / -80 - 20 °C View Scheme

toluene-4-sulfonic acid in benzene Heating;