Swern oxidation; (further oxidizing agents);

sodium periodate in diethyl ether; water 2 h; Ambient temperature;

dimethyl sulfoxide; triethylamine in dichloromethane

1: 100 percent / LDA / tetrahydrofuran / 1.75 h / -70 - -15 °C 2: 1). Et3B; 2.) NaBH4, MeOH / 1.) THF, 23 deg C, 15 min; 2.) -70 deg C 3: 70 percent / p-toluenesulfonic acid / acetone / 2 h / 23 °C 4: 80 percent / Bu4NF / tetrahydrofuran / 3 h / 0 °C 5: 97 percent / Swern oxidation; (further oxidizing agents) View Scheme

1: 70 percent / p-toluenesulfonic acid / acetone / 2 h / 23 °C 2: 80 percent / Bu4NF / tetrahydrofuran / 3 h / 0 °C 3: 97 percent / Swern oxidation; (further oxidizing agents) View Scheme

1: 1). Et3B; 2.) NaBH4, MeOH / 1.) THF, 23 deg C, 15 min; 2.) -70 deg C 2: 70 percent / p-toluenesulfonic acid / acetone / 2 h / 23 °C 3: 80 percent / Bu4NF / tetrahydrofuran / 3 h / 0 °C 4: 97 percent / Swern oxidation; (further oxidizing agents) View Scheme

1: 99 percent / p-toluenesulfonic acid / 2 h / Ambient temperature 2: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 3: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature View Scheme

1: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 2: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature View Scheme

1: 1.) diethyl(methoxy)borane, 2.) sodium borohydride / 1.) THF, methanol, RT, 15 min, 2.) THF, methanol, a) -78 deg C, 4 h, b) from -78 deg C to RT, 8 h 2: 99 percent / p-toluenesulfonic acid / 2 h / Ambient temperature 3: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 4: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature View Scheme

1: 60 percent / DIBAL / tetrahydrofuran; hexane / 4 h / -78 °C 2: 1.) diethyl(methoxy)borane, 2.) sodium borohydride / 1.) THF, methanol, RT, 15 min, 2.) THF, methanol, a) -78 deg C, 4 h, b) from -78 deg C to RT, 8 h 3: 99 percent / p-toluenesulfonic acid / 2 h / Ambient temperature 4: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 5: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature View Scheme