1.1: MCPBA / hexane / 4 h / 20 °C 1.2: 0.8 g / Et3N*3HF / CH2Cl2 / 2 h / 20 °C 2.1: 88 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 20 °C 3.1: pyrrolidone hydrotribromide / tetrahydrofuran / 1 h / 20 °C 3.2: 71 percent / LiBr; Li2CO3 / dimethylformamide / 2 h / Heating View Scheme