1.1: n-BuLi / tetrahydrofuran / 2 h / -78 °C 1.2: 90 percent / tetrahydrofuran 2.1: 60 percent / Pd(OAc)2; (o-tolyl)3-phosphine; K2CO3 / dimethyl ether; H2O / 3 h / Heating 3.1: 60 percent / N-bromosuccinimide 4.1: t-BuLi / tetrahydrofuran / 1 h / -78 °C 4.2: 40 percent / tetrahydrofuran 5.1: 60 percent / HCl; acetic acid View Scheme