18-crown-6 ether; potassium hexamethylsilazane in tetrahydrofuran; toluene T=-78°C; 0.666667 h;

sodium hydride

sodium hydride in ethylene glycol dimethyl ether 1.) 0 deg C, 20 min; 2.) RT, 30 min; 3.) reflux, 8h;

1: 1.) sodium hydride / 1.) ether, 25 deg C, 45 min, 2.) 3 h 2: 98 percent / hydrogen / 5percent Pd-C / methanol / 12 h / 25 °C 3: 86 percent / hydrochloric acid / diethyl ether / 1 h / 25 °C View Scheme

sodium hydride

(i) NaH, (ii) /BRN= 605330/; Multistep reaction;

1: 2-(Diethoxy-phosphoryl)-propionic acid ethyl ester With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; Inert atmosphere; 2: tetrahydropyran-2-one With diisobutylaluminium hydride in tetrahydrofuran; hexane T=-78°C; Inert atmosphereWarming; 3: With water; ammonium chloride in tetrahydrofuran; hexane optical yield given as percent de;

sodium ethanolate in ethanol T=20°C; 2 h;

lithium tert-butylate in hexane T=20°C; 1 h;

1: 1.) NaH / 1.) THF, RT, 1 h, 2.) THF, RT, 3 h 2: 68 percent / RuCl3, NaIO4, H2O / ethyl acetate; acetonitrile / 0.25 h / 0 °C 3: 85 percent / p-TsOH / CH2Cl2 / 1.) RT, 2 h, 2.) reflux, 2.5 h 4: 70 percent / SmI2, HMPA, ethylene glycol / tetrahydrofuran / 3.5 h / Ambient temperature 5: 1.) DMSO, (CF3CO)2O, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 15 min, 2.) CH2Cl2, -78 deg C, 30 min 6: 1.) NaH, HMPA / 1.) THF, 0 deg C, 1 h, 2.) THF, RT, 6.5 h 7: tetrabutylammonium fluoride / tetrahydrofuran / 2.5 h / 0 °C 8: 77 percent / PCC, AcONa, molecular sieves 3 Angstroem / CH2Cl2 / 1 h / Ambient temperature 9: 1.) n-BuLi / 1.) THF, -20 deg C, 15 min, 2.) THF, -20 deg C, 3 h 10: 1.) DMSO, (CF3CO)2O, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min, 2.) CH2Cl2, -78 deg C, 1 h 11: 88 percent / Ph3P / toluene / 8.5 h / Heating 12: 62 percent / 5percent HCl / methanol / 10 h / Ambient temperature View Scheme