1: 93 percent / BuLi / tetrahydrofuran; hexane / 0 - 20 °C 2: 75 percent / NaOEt / ethanol / 10 h / Heating 3: 55 percent / LiNbMoO6; H2O2 / methanol; benzene; H2O / 6 h / 20 °C 4: 90 percent / NaH; NaI / tetrahydrofuran / 15 h / 20 °C 5: 40 percent / urea; H2O2; phthalic anhydride / acetonitrile / 5 h / 0 °C 6: KOH / 2-methyl-propan-2-ol; CCl4 / 7 h / 20 °C 7: 78 percent / NaOEt / ethanol; benzene / 12 h / 90 °C View Scheme

lithium perchlorate; N(Et)4ClO4 in 1,2-dichloro-ethane T=55°C; 0.416667 h; electrolysis; electrogenerated acid-catalyzed cyclization of isoprenoids;

1: 78 percent / SeO2, t-BuOOH / CH2Cl2 / 25 h / 20 °C 2: 1.) Ti(OiPr)4, CaH2, 4A molecular sieves, D-(-)-DET, 2.) tert-BuOOH / 1.) CH2Cl2, -20 deg C, 15 min, 2.) CH2Cl2, toluene, -40 deg C, 5 h 3: 1.) LDA / 1.) THF, hexane, -78 deg C, 40 min, 2.) THF, hexane, from -78 deg C to RT, 2 h 4: 78 percent / Li, EtNH2 / tetrahydrofuran / 4 h / -78 °C 5: 1.) Ph3P, N-chlorosuccinimide / 1.) THF, 20 deg C, 5 h, 2.) THF, 3 h 6: 98 percent / imidazole / dimethylformamide / 10 h / 50 °C 7: LDA, DABCO / tetrahydrofuran; hexane / 48 h / -78 °C 8: Bu4N+F- / tetrahydrofuran / 24 h / 15 °C 9: 70 percent / Li, EtNH2 / tetrahydrofuran / 3.5 h / -78 °C 10: 49 percent / SOCl2, pyridine / 3 h / 15 °C 11: 92 percent / MnO2 / hexane / 12 h / 15 °C 12: 65 percent / 67 percent aq. Ca(ClO)2, glacial acetic acid / acetonitrile / 20 h / 15 °C View Scheme

1: 78 percent / SeO2, t-BuOOH / CH2Cl2 / 25 h / 20 °C 2: 1.) Ti(OiPr)4, CaH2, 4A molecular sieves, D-(-)-DET, 2.) tert-BuOOH / 1.) CH2Cl2, -20 deg C, 15 min, 2.) CH2Cl2, toluene, -40 deg C, 5 h 3: 1.) LDA / 1.) THF, hexane, -78 deg C, 40 min, 2.) THF, hexane, from -78 deg C to RT, 2 h 4: 78 percent / Li, EtNH2 / tetrahydrofuran / 4 h / -78 °C 5: 1.) Ph3P, N-chlorosuccinimide / 1.) THF, 20 deg C, 5 h, 2.) THF, 3 h 6: 98 percent / imidazole / dimethylformamide / 10 h / 50 °C 7: LDA, DABCO / tetrahydrofuran; hexane / 48 h / -78 °C 8: Bu4N+F- / tetrahydrofuran / 24 h / 15 °C 9: 70 percent / Li, EtNH2 / tetrahydrofuran / 3.5 h / -78 °C 10: 49 percent / SOCl2, pyridine / 3 h / 15 °C 11: 92 percent / MnO2 / hexane / 12 h / 15 °C View Scheme

1: 78 percent / SeO2, t-BuOOH / CH2Cl2 / 25 h / 20 °C 2: 1.) Ti(OiPr)4, CaH2, 4A molecular sieves, D-(-)-DET, 2.) tert-BuOOH / 1.) CH2Cl2, -20 deg C, 15 min, 2.) CH2Cl2, toluene, -40 deg C, 5 h 3: 1.) LDA / 1.) THF, hexane, -78 deg C, 40 min, 2.) THF, hexane, from -78 deg C to RT, 2 h 4: 78 percent / Li, EtNH2 / tetrahydrofuran / 4 h / -78 °C 5: 1.) Ph3P, N-chlorosuccinimide / 1.) THF, 20 deg C, 5 h, 2.) THF, 3 h 6: 98 percent / imidazole / dimethylformamide / 10 h / 50 °C 7: LDA, DABCO / tetrahydrofuran; hexane / 48 h / -78 °C 8: Bu4N+F- / tetrahydrofuran / 24 h / 15 °C 9: 70 percent / Li, EtNH2 / tetrahydrofuran / 3.5 h / -78 °C View Scheme

tert.-butylhydroperoxide; selenium(IV) oxide; 4-hydroxy-benzoic acid in dichloromethane modified Sharpless oxidation;

sulfuric acid in acetic acid T=12°C; 0.5 h;

lithium perchlorate; N(Et)4ClO4 in 1,2-dichloro-ethane T=55°C; 0.416667 h; electrolysis; electrogenerated acid-catalyzed cyclization of isoprenoids;