1.1: sodium nitrite; hypophosphorous acid / H2O / 12 h / 20 °C 1.2: 87 percent / water / 6 h / 5 °C / pH 6 - 7 2.1: 90 percent / silver carbonate / CH2Cl2 / 24 h 3.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 3.2: 89 percent / tetrahydrofuran; hexane / 0.5 h / -78 °C 4.1: m-CPBA; p-toluenesulfonic acid / CHCl3 / 24 h / 20 °C 5.1: 0.15 g / KOH / methanol / 2 h / Heating View Scheme

1.1: 67 percent / 1,3-dibromo-5,5-dimethylhydantoin / CH2Cl2 / 0.75 h / -40 °C 2.1: sodium nitrite; hypophosphorous acid / H2O / 12 h / 20 °C 2.2: 87 percent / water / 6 h / 5 °C / pH 6 - 7 3.1: 90 percent / silver carbonate / CH2Cl2 / 24 h 4.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 4.2: 89 percent / tetrahydrofuran; hexane / 0.5 h / -78 °C 5.1: m-CPBA; p-toluenesulfonic acid / CHCl3 / 24 h / 20 °C 6.1: 0.15 g / KOH / methanol / 2 h / Heating View Scheme

1.1: 90 percent / silver carbonate / CH2Cl2 / 24 h 2.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: 89 percent / tetrahydrofuran; hexane / 0.5 h / -78 °C 3.1: m-CPBA; p-toluenesulfonic acid / CHCl3 / 24 h / 20 °C 4.1: 0.15 g / KOH / methanol / 2 h / Heating View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 1.2: 89 percent / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.1: m-CPBA; p-toluenesulfonic acid / CHCl3 / 24 h / 20 °C 3.1: 0.15 g / KOH / methanol / 2 h / Heating View Scheme

1: m-CPBA; p-toluenesulfonic acid / CHCl3 / 24 h / 20 °C 2: 0.15 g / KOH / methanol / 2 h / Heating View Scheme