1.1: Me4NB(OAc)3H / acetic acid; acetonitrile / 24 h / -40 °C 1.2: 96 percent / 2,6-lutidine / CH2Cl2 / 2.5 h / -78 °C 2.1: 99 percent / H2 / Pd(OH)2 / ethyl acetate; methanol / 23 °C 3.1: 74 percent / PhSO2Cl; pyridine / 48 h / 0 °C 4.1: 70 percent / TBAF; AcOH / tetrahydrofuran / 4 h / 0 °C View Scheme

1.1: Me4NB(OAc)3H / acetic acid; acetonitrile / 24 h / -40 °C 1.2: 96 percent / 2,6-lutidine / CH2Cl2 / 2.5 h / -78 °C 2.1: 99 percent / H2 / Pd(OH)2 / ethyl acetate; methanol / 23 °C 3.1: 74 percent / PhSO2Cl; pyridine / 48 h / 0 °C 4.1: 70 percent / TBAF; AcOH / tetrahydrofuran / 4 h / 0 °C 5.1: 90 percent / PPh3; DIAD / tetrahydrofuran / 23 °C View Scheme

1.1: Me4NB(OAc)3H / acetic acid; acetonitrile / 24 h / -40 °C 1.2: 96 percent / 2,6-lutidine / CH2Cl2 / 2.5 h / -78 °C 2.1: 99 percent / H2 / Pd(OH)2 / ethyl acetate; methanol / 23 °C 3.1: 74 percent / PhSO2Cl; pyridine / 48 h / 0 °C 4.1: 70 percent / TBAF; AcOH / tetrahydrofuran / 4 h / 0 °C View Scheme