1: With n-butyllithium; potassium tert-butylate; diisopropylamine in tetrahydrofuran; hexane T=-78°C; Metallation; 3 h; 2: With boric acid trimethyl ester in tetrahydrofuran; hexane T=0°C; boronation; 2 h; 3: With dihydrogen peroxide in tetrahydrofuran; hexane; water T=20°C; Oxidation; 1 h;

1.1: 92 percent / pyridinium p-toluenesulfonate / CH2Cl2 / 3 h / Heating 2.1: LDA; t-BuOK / hexane; tetrahydrofuran / 3.5 h / -78 °C 2.2: (MeO)3B / hexane; tetrahydrofuran / 2 h 2.3: aq. H2O2 / hexane; tetrahydrofuran / 1 h / 20 °C View Scheme

1.1: pyridinium p-toluenesulfonate / dichloromethane / |Reflux 2.1: lithium diisopropyl amide; potassium tert-butylate / tetrahydrofuran / -78 °C 2.2: 0 °C 3.1: dihydrogen peroxide / water / 25 °C View Scheme

1: 92 percent / (PhO)3PCH3I, DMAP / dimethylformamide / 20 h / Ambient temperature 2: 93 percent / p-TsOH*H2O / methanol / 2 h / Ambient temperature View Scheme

1: 73 percent / TEMPO, aq. KBr, 15percent NaClO, NaHCO3 / CH2Cl2 2: 80 percent / AcCl in MeOH / Heating View Scheme