1.1: (diethylamino)diphenylsilyllithium; diethyl zinc / tetrahydrofuran; hexane / -78 °C 1.2: 57 percent / m-chloroperoxybenzoic acid; KHF2 / dimethylformamide / 2 h / 20 °C 2.1: 58 percent / BuLi; HMPA; diisopropylamine / hexane; tetrahydrofuran / 4 h / -78 °C 3.1: 355 mg / trifluoroacetic acid / CH2Cl2 / 3 h / 20 °C 4.1: NaOH / H2O / 64 h / 4 °C 5.1: 149 mg / triethylamine; bis(2-oxo-3-oxazolidinyl)phosphinic chloride / CH2Cl2 / 2 h / 20 °C View Scheme

1.1: (diethylamino)diphenylsilyllithium; diethyl zinc / tetrahydrofuran; hexane / -78 °C 1.2: 57 percent / m-chloroperoxybenzoic acid; KHF2 / dimethylformamide / 2 h / 20 °C 2.1: 58 percent / BuLi; HMPA; diisopropylamine / hexane; tetrahydrofuran / 4 h / -78 °C 3.1: 355 mg / trifluoroacetic acid / CH2Cl2 / 3 h / 20 °C 4.1: NaOH / H2O / 64 h / 4 °C View Scheme