(i) aq. Hg(OAc)2, THF, (ii) NaBH4, aq. NaOH; Multistep reaction;

potassium hydroxide

1.1: 87 percent / AD-mix-β; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 50 h / 20 °C 2.1: pyridine / CHCl3 / 3 h / 20 °C 3.1: 1.8 g / K2CO3 / methanol; H2O / 15 h / 20 - 40 °C 4.1: aq. hydrobromic acid / CHCl3; acetic acid / 1.5 h / 20 °C 4.2: 44 percent / tributyltin hydride; α,α'-azobis(isobutyronitrile) / benzene / 1 h / Heating View Scheme

1: 87 percent / AD-mix-β; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 50 h / 20 °C 2: pyridine / CHCl3 / 3 h / 20 °C 3: 1.8 g / K2CO3 / methanol; H2O / 15 h / 20 - 40 °C View Scheme