1: 3-iodo-3-methoxy-O-triisopropylsilylphenol; 1-ethynyl-cyclohexan-1-ol With copper(l) iodide; diisopropylamine; bis-triphenylphosphine-palladium(II) chloride T=80°C; Sonogashira coupling; 2: 2-iodo-5-methoxy-O-triisopropylsilylphenol With potassium hydroxide; copper(l) iodide; bis-triphenylphosphine-palladium(II) chloride T=80°C; Sonogashira coupling; 3: With tetrabutyl ammonium fluoride in tetrahydrofuran T=80°C; Further stages.;

sodium methylate in methanol 20 h; Heating;

1: KOAc / acetic anhydride / 10 h / 150 °C 2: LAH; AlCl3 / diethyl ether; tetrahydrofuran / 1.5 h 3: 65 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / 7.5 h / Heating 4: hydrogen / Pd-C / ethanol View Scheme

1: LAH; AlCl3 / diethyl ether; tetrahydrofuran / 1.5 h 2: 65 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / 7.5 h / Heating 3: hydrogen / Pd-C / ethanol View Scheme

1: LAH; AlCl3 / diethyl ether; tetrahydrofuran / 1.5 h 2: 65 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / 7.5 h / Heating 3: hydrogen / Pd-C / ethanol View Scheme

1: KOAc / acetic anhydride / 10 h / 150 °C 2: LAH; AlCl3 / diethyl ether; tetrahydrofuran / 1.5 h 3: 65 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / 7.5 h / Heating 4: hydrogen / Pd-C / ethanol View Scheme

hydrogenchloride; acetic acid T=80°C; 24 h; also prepared by 1) H2, Pd/C, EtOAc, 2) HCl, HOAc, RT, or with HBr/HOAc, reflux, 35-45 min;

1: K2CO3 / acetone / 21 h / Heating 2: 15.0 g / acetone / 3 h / Heating 3: 94 percent / KI; CuI / hexamethylphosphoric acid triamide / 3 h / 150 °C 4: 98 percent / CuI; Et3N / PdCl2(PPh3)2 / dimethylformamide / 1 h / 20 °C 5: 99 percent / TBAF / tetrahydrofuran / 0.17 h / 20 °C 6: 96 percent / CuI; i-Pr2NH / PdCl2(PPh3)2 / dimethylformamide / 1.5 h / 60 °C 7: 81 percent / DIBAL-H / toluene; CH2Cl2 / 3 h / -78 °C 8: 67 percent / TBAF / tetrahydrofuran / 3 h / Heating 9: 78 percent / NaOMe / methanol / 20 h / Heating View Scheme

1: 15.0 g / acetone / 3 h / Heating 2: 94 percent / KI; CuI / hexamethylphosphoric acid triamide / 3 h / 150 °C 3: 98 percent / CuI; Et3N / PdCl2(PPh3)2 / dimethylformamide / 1 h / 20 °C 4: 99 percent / TBAF / tetrahydrofuran / 0.17 h / 20 °C 5: 96 percent / CuI; i-Pr2NH / PdCl2(PPh3)2 / dimethylformamide / 1.5 h / 60 °C 6: 81 percent / DIBAL-H / toluene; CH2Cl2 / 3 h / -78 °C 7: 67 percent / TBAF / tetrahydrofuran / 3 h / Heating 8: 78 percent / NaOMe / methanol / 20 h / Heating View Scheme

hydrogen; palladium on activated charcoal in ethanol