n-butyllithium in tetrahydrofuran; pentane T=-78 - 23°C; Corey-Fuchs reaction; 3 h;

1: With lithium diisopropyl amide in tetrahydrofuran T=-78°C; 1 h; 2: With diethyl chlorophosphate in tetrahydrofuran T=-78 - 20°C; 3 h; 3: With water; lithium diisopropyl amide Product distribution / selectivity; more than 3 stages;

1.1: 88 percent / K2CO3 / dimethylformamide / 6 h / 100 °C 2.1: LDA / tetrahydrofuran; heptane; ethylbenzene / 1 h / -78 °C 2.2: 56 percent / tetrahydrofuran; heptane; ethylbenzene / 3 h / 20 °C 3.1: 1.33 g / LDA / pentane; heptane; ethylbenzene / 3 h / 20 °C View Scheme

1: 96 percent / PPh3 / CH2Cl2 / 0.67 h / cooling 2: 99 percent / nBuLi / pentane; tetrahydrofuran / 3 h / -78 - 23 °C View Scheme