1: 1.) CuBr*DMS / 1.) THF, Et2O, -40 deg C, 40 min, 2.) -78 deg C, 90 min 2: 59 percent / DIBALH / tetrahydrofuran; hexane / 2 h / -40 - 0 °C 3: 1.) MsCl, Et3N, 2.) LiCl / 1.) CH2Cl2, -40 deg C, 1 h, 2.) THF, 0 deg C, 2 h View Scheme

1: 59 percent / DIBALH / tetrahydrofuran; hexane / 2 h / -40 - 0 °C 2: 1.) MsCl, Et3N, 2.) LiCl / 1.) CH2Cl2, -40 deg C, 1 h, 2.) THF, 0 deg C, 2 h View Scheme

N-chloro-succinimide; dimethylsulfide

(i) dioxane, Et2O, (ii) /BRN= 3660023/, (iii) /BRN= 1900390/; Multistep reaction;