1: 65percent aq. acetic acid / tetrahydrofuran / 50 °C 2: 82 percent / imidazole / dimethylformamide / 23 °C 3: 33 percent / H2 / (methyl benzoate)*Cr(CO)3 / acetone / 15 h / 120 °C / 51485.6 Torr 4: 88 percent / tetrabutylammonium fluoride (TBAF) / tetrahydrofuran / 23 °C 5: 100 percent / 10percent aq. NaOH / methanol / 0 °C View Scheme