1: 52 percent / Et3N / CH2Cl2 / 4 h / 0 °C 2: Jones' reagent / acetone / 3 h / 0 °C View Scheme

4-(N,N-dimethlyamino)pyridine; potassium carbonate in dichloromethane T=40°C; 0.5 h; Microwave irradiation; optical yield given as percent ee;

1: 92 percent / Et3N / CH2Cl2 / 1) 0 deg C, 1 h, 2) room temperature, 4 h 2: 1) TsCl, Et3N, DMAP, 2) NaH / 1) CH2Cl2, 0 deg C to room temperature, overnight, 2) THF, 0 deg C to room temperature; room temperature, 24 h View Scheme

1: 90 percent / triethylamine / tetrahydrofuran / 2 h 2: 90 percent / polystyryl diphenylphosphine, imidazole, iodine / CH2Cl2 / 1 h / Heating 3: 82 percent / CH2Cl2 / 4 h / Heating View Scheme

1: 52 percent / Et3N / CH2Cl2 / 4 h / 0 °C 2: Jones' reagent / acetone / 3 h / 0 °C 3: 57 percent / DCC / CH2Cl2 / 10 h / Ambient temperature 4: 100 percent / Jones' reagent View Scheme

1: 71 percent / 4-dimethylaminopyridine, Et3N / CH2Cl2 / 15 h / 0 °C 2: 75 percent / potassium t-butoxide 3: 90 percent / HBr / H2O / 16 h / Heating 4: 67 percent / dioxane / 16 h / Heating 5: 57 percent / NaH / tetrahydrofuran / 1.08 h 6: lithium hexamethyldisilazide / tetrahydrofuran; hexane / 8.5 h / -78 °C 7: 80 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 4 h / -78 °C 8: H2O2, m-chloroperoxybenzoic acid / CHCl3; H2O / 0.75 h / -50 - 0 °C 9: toluene / 5 h / 90 °C 10: NaOH / methanol / 2 h / Ambient temperature 11: 1.) trimethylsilyl chlorid, lithium isopropylamide / 1.) THF/hexane, -78 degC, 3 h 2.) THF, 0 degC, 3 h 12: 58 percent / H2O2 / pyridine; CH2Cl2; H2O / 18 h / Ambient temperature 13: 90 percent / HCl / methanol; H2O / 1 h / Ambient temperature View Scheme

(bromination);