B-chloro-diisopinocampheylborane in dichloromethane T=-78°C; 3.5 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: Zn, NH4Cl / tetrahydrofuran; H2O / 1.3 h / Ambient temperature 2: 61 percent / tetrahydrofuran / 3 h / Ambient temperature 3: (+)-Ipc2BCl / CH2Cl2 / 6 h / -78 °C View Scheme

1: 61 percent / tetrahydrofuran / 3 h / Ambient temperature 2: (+)-Ipc2BCl / CH2Cl2 / 6 h / -78 °C View Scheme