1.1: 0.758 g / LiBr; TEA / CHCl3 / 12 h / 0 - 5 °C 2.1: (-)-dibenzoyl-L-tartaric acid / acetonitrile; H2O / 60 °C 2.2: 226 mg / NaOH / CHCl3; H2O / pH 9 3.1: 77 percent / tBuOK / tetrahydrofuran; 2-methyl-propan-2-ol / 0.33 h / 0 °C 4.1: aq. HCl / 0.5 h / Heating View Scheme

1.1: 0.758 g / LiBr; TEA / CHCl3 / 12 h / 0 - 5 °C 2.1: (-)-dibenzoyl-L-tartaric acid / acetonitrile; H2O / 60 °C 2.2: 226 mg / NaOH / CHCl3; H2O / pH 9 3.1: 77 percent / tBuOK / tetrahydrofuran; 2-methyl-propan-2-ol / 0.33 h / 0 °C 4.1: NaOMe / methanol / 0.5 h / Heating 4.2: HCl / 0.75 h / Heating View Scheme