1.1: 92 percent / aq. AcOH / 20 h / 20 °C 2.1: NaIO4; SiO2 / CH2Cl2; H2O / 0.5 h / 20 °C 2.2: KHMDS / tetrahydrofuran; toluene / 1 h / -78 °C 2.3: 50 percent / tetrahydrofuran; toluene; CH2Cl2 / 4 h / 20 °C 3.1: 88 percent / Dess-Martin periodinane / CH2Cl2 / 30 h / 20 °C View Scheme

1.1: 92 percent / aq. AcOH / 20 h / 20 °C 2.1: NaIO4; SiO2 / CH2Cl2; H2O / 0.5 h / 20 °C 2.2: KHMDS / tetrahydrofuran; toluene / 1 h / -78 °C 2.3: 50 percent / tetrahydrofuran; toluene; CH2Cl2 / 4 h / 20 °C View Scheme

acetic acid T=20°C; 20 h;