1: 1) NaBH4 / 1) ethanol, room temperature, 2) ethanol, room temperature 2: diethyl ether / 0.67 h / -78 °C 3: m-CPBA, KH2PO4 / methanol / Ambient temperature View Scheme

1: diethyl ether / 0.67 h / -78 °C 2: m-CPBA, KH2PO4 / methanol / Ambient temperature View Scheme

1: 1) NaBH4 / 1) ethanol, room temperature, 2) ethanol, room temperature 2: diethyl ether / 0.67 h / -78 °C 3: m-CPBA, KH2PO4 / methanol / Ambient temperature View Scheme

sodium hydride in tetrahydrofuran Ambient temperature;