in water T=40°C; 1.5 h;

in water

in water T=20°C; hereto-Diels-Alder reaction; 72 h; optical yield given as percent de;

1: 100 percent / PPh3, diethyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature 2: 87 percent / thiourea, NaHCO3 / ethanol / 2 h / 95 °C 3: 91 percent / i-Pr2EtN / CH2Cl2 / 24 h 4: 100 percent / diisobutylaluminium hydride / tetrahydrofuran / 2 h / -78 °C 5: 80 percent / toluene / 6 h / 95 °C 6: 60 percent / pyridinium chlorochromate, toluene-p-sulfonic acid / CH2Cl2 / 12 h / Ambient temperature 7: 87 percent / MeLi, CuCN / tetrahydrofuran / 0.5 h / -78 °C 8: 50 percent / DIBAL-H / diethyl ether / 1 h / -78 °C 9: 87 percent / i-Pr2EtN / CH2Cl2 / 12 h / Ambient temperature 10: 1.) aq. HCl, 2.) LiOH / 1.) THF, room temperature, 14 h, 2.) H2O, MeOH, room temperature, 10 h 11: 1.) Et3N, 2,4,6-trichlorobenzoyl chloride, 2.) N,N-dimethylaminopyridine / 1.) THF, room temperature, 6 h, 2.) toluene, reflux, 14 h 12: 85 percent / TiCl4 / CH2Cl2 / 2 h / 0 °C View Scheme