2: 2N HCl / 0.05 h / 0 °C 4: 95 percent / diisobutylaluminium hydride / CH2Cl2 5: DMAP, Et3N / CH2Cl2 / 0.5 h / 0 °C 6: LiCl / dimethylformamide / 0.5 h / 0 °C 8: O2, rose bengal / CH2Cl2; methanol / -78 °C / Irradiation 9: 2N hydrochloric acid / tetrahydrofuran / 2 h / Ambient temperature 10: Irradiation View Scheme