1.1: n-BuLi / tetrahydrofuran; petroleum ether / 1 h / -78 °C 1.2: 80 percent / tetrahydrofuran / 16 h / 20 °C 2.1: bromotrimethylsilane / CH2Cl2 / 20 °C 2.2: 93 percent / methanol View Scheme