lithium hexamethyldisilazane in tetrahydrofuran T=-78 - 20°C; 4 h;

1.1: 80 percent / Dibal-H / diethyl ether; hexane / -70 °C 2.1: 80 percent / K2CO3 / methanol 3.1: n-butyllithium / hexane; tetrahydrofuran / -78 °C 3.2: 90 percent / hexane; tetrahydrofuran / -78 - 20 °C View Scheme

diisobutylaluminium hydride in diethyl ether; hexane T=-70°C;

1: 80 percent / Dibal-H / diethyl ether; hexane / -70 °C 2: 80 percent / K2CO3 / methanol View Scheme