1: 92 percent / Et3N, 4-N,N-dimethylaminopyridine (DMAP) / CH2Cl2 / 8 h / Ambient temperature 2: 89 percent / aq LiOH / tetrahydrofuran / 24 h / Ambient temperature View Scheme

1: 92 percent / Et3N, 4-N,N-dimethylaminopyridine (DMAP) / CH2Cl2 / 8 h / Ambient temperature 2: aq LiOH / tetrahydrofuran / 24 h / Ambient temperature 3: 89 percent / NaH / dimethylformamide / 21 h / Ambient temperature 4: 80 percent / 48percent aq NaOH / 120 °C View Scheme

TPPBr2; triethylamine in chloroform T=-60 - 20°C; von Braun degradation;

1: 92 percent / Et3N, 4-N,N-dimethylaminopyridine (DMAP) / CH2Cl2 / 8 h / Ambient temperature 2: aq LiOH / tetrahydrofuran / 24 h / Ambient temperature 3: 89 percent / NaH / dimethylformamide / 21 h / Ambient temperature View Scheme