1: (COCl)2 / 0 - 20 °C 2: pyridine 3: BBr3 / CH2Cl2 / 0.5 h / 0 °C 4: NaH / dimethylformamide 5: 1.) LDA / 1.) THF, -78 deg, 10 min 6: DDQ / dioxane / 0.17 h / 60 °C 7: K2CO3 / dimethylsulfoxide / 16 h / 20 °C 8: LAH / tetrahydrofuran / 1 h / 0 °C 9: pyridine / 24 h 10: imidazole / dimethylformamide / 16 h / 0 - 20 °C 11: TsOH / CH2Cl2; methanol / 0.08 h 12: 62 percent / PCC / CH2Cl2 / 20 °C 13: 91 percent / NBS / CH2Cl2 / 0.5 h / 20 °C 14: MCPBA, Na2SO4, 4,4'-methylenebis(2,6-di-t-butyl)phenol / benzene / 1 h / 20 °C 15: aq. NaOH / methanol; tetrahydrofuran / 20 °C 16: K2CO3 / dimethylsulfoxide / 16 h / 20 °C 17: TBAF 18: DEAD, PPh3 19: NaOH 21: 1.) t-BuLi, 2.) FeCl3 / 1.) THF, -78 deg, 2.) -78 deg to 20 deg 22: 1.) TBAF, 2.) H2 / 2.) Pd/C / 1.) THF, 2.) THF, MeOH 23: 65 percent / K3Fe(CN)6, NaOH / H2O; ethanol; tetrahydrofuran / 20 °C 24: 54 percent / DMAP, pyridine 25: aq. HCl View Scheme

1: LDA 2: K2CO3 View Scheme

1: methyl 2,4-dimethoxy-6-methylbenzoate With lithium diisopropyl amide in tetrahydrofuran; cyclohexane T=-78°C; 0.333333 h; 2: 4-methoxy-6-methyl-2H-pyran-2-one in tetrahydrofuran; cyclohexane T=-78 - 20°C;

1: 1.) LDA / tetrahydrofuran / 1.) -78 deg C, 15 min, 2.) -78 deg C-room temperature, 4 h 2: 81 percent / water / 16 h 3: 91 percent / acetyl chloride / 0.5 h / Heating 4: 67 percent / pyridine / tetrahydrofuran / 1.) room temperature, 40 min, 2.) reflux, 1 h 5: 91 percent / 0.17 h / 140 - 150 °C 6: 70 percent / sodium borohydride / 1 h / Heating View Scheme

1: 1.) LDA / tetrahydrofuran / 1.) -78 deg C, 15 min, 2.) -78 deg C-room temperature, 4 h 2: 81 percent / water / 16 h 3: 91 percent / acetyl chloride / 0.5 h / Heating 4: 67 percent / pyridine / tetrahydrofuran / 1.) room temperature, 40 min, 2.) reflux, 1 h 5: 91 percent / 0.17 h / 140 - 150 °C 6: 70 percent / sodium borohydride / 1 h / Heating 7: 80 percent / aluminium chloride / nitrobenzene / 6 h / 50 - 60 °C View Scheme

1: 1.) LDA / tetrahydrofuran / 1.) -78 deg C, 15 min, 2.) -78 deg C-room temperature, 4 h 2: 81 percent / water / 16 h 3: 91 percent / acetyl chloride / 0.5 h / Heating View Scheme

chromium(VI) oxide T=0°C;

1: (COCl)2 / 0 - 20 °C 2: pyridine 3: BBr3 / CH2Cl2 / 0.5 h / 0 °C View Scheme

1.1: LDA / tetrahydrofuran; cyclohexane / 0.33 h / -78 °C 1.2: 32 percent / tetrahydrofuran; cyclohexane / -78 - 20 °C 2.1: 85 percent / BBr3 / CH2Cl2 / 7 h / 20 °C View Scheme