1.1: 87 percent / mesyl chloride; N,N-diisopropylethylamine / CH2Cl2 / 0.83 h / 0 - 20 °C 2.1: methylmagnesium iodide / diethyl ether; tetrahydrofuran / 1 h / -10 - 20 °C 2.2: diethyl ether; tetrahydrofuran / 2 h / -10 - 20 °C 3.1: 99 percent / sodium hydride / tetrahydrofuran / 1 h / 20 °C View Scheme

1.1: 87 percent / mesyl chloride; N,N-diisopropylethylamine / CH2Cl2 / 0.83 h / 0 - 20 °C 2.1: methylmagnesium iodide / diethyl ether; tetrahydrofuran / 1 h / -10 - 20 °C 2.2: diethyl ether; tetrahydrofuran / 2 h / -10 - 20 °C View Scheme

1.1: 87 percent / mesyl chloride; N,N-diisopropylethylamine / CH2Cl2 / 0.83 h / 0 - 20 °C 2.1: methylmagnesium iodide / diethyl ether; tetrahydrofuran / 1 h / -10 - 20 °C 2.2: 63 percent / diethyl ether; tetrahydrofuran / 2 h / -10 - 20 °C 3.1: 85 percent / aq. NaOH / methanol / 3 h / Heating View Scheme