1: 14.64 g / silica gel / CH2Cl2; H2O / 72 h / 20 °C 2: 97 percent / DMSO; oxalyl chloride; Et3N / CH2Cl2 / 1.5 h / -60 - 20 °C View Scheme

silica gel in dichloromethane; water T=20°C; 72 h;

water; silica gel in dichloromethane T=20°C; 96 h; Product distribution / selectivity;

1.1: 14.64 g / silica gel / CH2Cl2; H2O / 72 h / 20 °C 2.1: 97 percent / DMSO; oxalyl chloride; Et3N / CH2Cl2 / 1.5 h / -60 - 20 °C 3.1: Cu(OAc)2*H2O; 2,2-bis[(3aS,8aR)-3a,8,8a-3H-indeno[3,2-d]oxazol-2yl]propane / ethanol / 120 h / 20 °C 3.2: 2,6-lutidine / CH2Cl2 / 16.5 h / 0 - 20 °C 3.3: HCO2NH4 / Pd/C / methanol / 24 h / 20 °C 4.1: 2.252 g / Et3N / CH2Cl2 / 70 h / 20 °C 5.1: 64 percent / (+/-)-camphorsulfonic acid; ethylene glycol / tetrahydrofuran / 48 h / 50 °C 6.1: 83 percent / TEMPO; sodium phosphate buffer; aq. NaClO2 / aq. NaOCl / acetonitrile / 4.5 h / 35 °C / pH 6.7 View Scheme