1.1: 93 percent / oxalyl chloride; DMSO / CH2Cl2 / 1.5 h / -78 °C 2.1: (+)-TADDOL; Ti(O-i-Pr)4 / toluene; hexane / 12 h / -25 °C 3.1: triethylamine; DMAP / CH2Cl2 / 20 h / 20 °C 4.1: water; DDQ / CH2Cl2 / 1 h / 20 °C 5.1: 2-iodoxybenzoic acid / tetrahydrofuran; dimethylsulfoxide / 0.5 h / 20 °C 6.1: potassium tert-butoxide / tetrahydrofuran / 0.08 h / -78 °C 6.2: tetrahydrofuran / -78 - 20 °C 7.1: potassium hydroxide / methanol / 3 h / 20 °C View Scheme

1.1: triethylamine; DMAP / CH2Cl2 / 20 h / 20 °C 2.1: water; DDQ / CH2Cl2 / 1 h / 20 °C 3.1: 2-iodoxybenzoic acid / tetrahydrofuran; dimethylsulfoxide / 0.5 h / 20 °C 4.1: potassium tert-butoxide / tetrahydrofuran / 0.08 h / -78 °C 4.2: tetrahydrofuran / -78 - 20 °C 5.1: potassium hydroxide / methanol / 3 h / 20 °C View Scheme

1.1: water; DDQ / CH2Cl2 / 1 h / 20 °C 2.1: 2-iodoxybenzoic acid / tetrahydrofuran; dimethylsulfoxide / 0.5 h / 20 °C 3.1: potassium tert-butoxide / tetrahydrofuran / 0.08 h / -78 °C 3.2: tetrahydrofuran / -78 - 20 °C 4.1: potassium hydroxide / methanol / 3 h / 20 °C View Scheme