tetrabutyl ammonium fluoride; acetic acid in tetrahydrofuran T=0°C; 0.166667 h;

boron tribromide in dichloromethane T=-78°C; 0.25 h;

1: 67 percent / TMSOTf; Et3N / toluene; CH2Cl2 / 0.25 h / 20 °C 2: 69 percent / MeNH2 / methanol / 3 h / 20 °C 3: 93 percent / dimethylformamide / 9 h / 50 °C 4: 89 percent / TBAF; AcOH / tetrahydrofuran / 0.17 h / 0 °C View Scheme

1: 93 percent / dimethylformamide / 9 h / 50 °C 2: 89 percent / TBAF; AcOH / tetrahydrofuran / 0.17 h / 0 °C View Scheme

1: 69 percent / MeNH2 / methanol / 3 h / 20 °C 2: 93 percent / dimethylformamide / 9 h / 50 °C 3: 89 percent / TBAF; AcOH / tetrahydrofuran / 0.17 h / 0 °C View Scheme

1: 75 percent / BF3*Et2O / 48 h / 0 °C 2: 80 percent / Ph3P, DEAD / tetrahydrofuran / 3 h / Ambient temperature 3: 91 percent / K2CO3 / CH2Cl2; methanol / 1 h / Ambient temperature 4: 1.) MsCl, pyridine, 2.) NBu4I, BaCO3, pyridine 5: Hg(OAc)2 6: 1.) BSA, 2.) TMSTf / 1.) MeCN, reflux, 2.) room temperature, 7 h 7: 69 percent / BBr3 / CH2Cl2 / 0.25 h / -78 °C View Scheme

1: 1.) BSA, 2.) TMSTf / 1.) MeCN, reflux, 2.) room temperature, 7 h 2: 69 percent / BBr3 / CH2Cl2 / 0.25 h / -78 °C View Scheme

1: Hg(OAc)2 2: 1.) BSA, 2.) TMSTf / 1.) MeCN, reflux, 2.) room temperature, 7 h 3: 69 percent / BBr3 / CH2Cl2 / 0.25 h / -78 °C View Scheme

1: 80 percent / Ph3P, DEAD / tetrahydrofuran / 3 h / Ambient temperature 2: 91 percent / K2CO3 / CH2Cl2; methanol / 1 h / Ambient temperature 3: 1.) MsCl, pyridine, 2.) NBu4I, BaCO3, pyridine 4: Hg(OAc)2 5: 1.) BSA, 2.) TMSTf / 1.) MeCN, reflux, 2.) room temperature, 7 h 6: 69 percent / BBr3 / CH2Cl2 / 0.25 h / -78 °C View Scheme

1: 1.) MsCl, pyridine, 2.) NBu4I, BaCO3, pyridine 2: Hg(OAc)2 3: 1.) BSA, 2.) TMSTf / 1.) MeCN, reflux, 2.) room temperature, 7 h 4: 69 percent / BBr3 / CH2Cl2 / 0.25 h / -78 °C View Scheme