in diethyl ether T=20°C; Grignard reaction;

1.1: DIBALH / toluene / 1 h / -78 °C 1.2: 80 percent / TEMPO; nBu4NCl; NaHCO3 / K2CO3; NCS / CH2Cl2; H2O 2.1: CuI / diethyl ether; hexane / 0.67 h / 0 °C 2.2: diethyl ether; hexane / 2.5 h / -78 - -15 °C 2.3: 47 percent / diethyl ether; hexane / -15 - 20 °C 3.1: 82 percent / diethyl ether / 20 °C View Scheme

oxygen; rose bengal; sodium sulfite 1.) methanol, irradiation, 7 h, 2.) methanol, 15 h; Yield given. Multistep reaction. Yields of byproduct given;

pyridinium chlorochromate in dichloromethane T=20°C;