ethyl bromide; magnesium in tetrahydrofuran 1.) -50 deg C, 1 h, 2.) -50 deg C, 1 h, -50 deg C to room temperature, 25 h;

1: 41 percent / 1.) n-butyl lithium, N,N,N,N-tetramethylethylenediamine / hexane / 1.) -50 deg C, 1 h, 2.) -50 deg C, 1 h, -50 deg C to room temperature, 25 h 2: 94 percent / 1.) magnesium, bromoethane / tetrahydrofuran / 1.) -50 deg C, 1 h, 2.) -50 deg C, 1 h, -50 deg C to room temperature, 25 h View Scheme