1.1: pyridinium chlorochromate / dichloromethane / 2.5 h / 0 - 20 °C / Inert atmosphere; Celite 2.1: toluene / 110 °C / Inert atmosphere; Molecular sieve; Sealed tube 2.2: 5.58 h / 0 - 20 °C / Molecular sieve 3.1: PHT / tetrahydrofuran / 72 h / 20 °C / Inert atmosphere 3.2: 12 h / 20 °C / Inert atmosphere 4.1: sodium tetrahydroborate / isopropyl alcohol / 77 h / 20 - 50 °C / Inert atmosphere View Scheme

<b>Multi-step reaction with 9 steps<br /> </b>1.1: water; acetic acid / 2 h / 20 - 50 &deg;C<br />2.1: 1H-imidazole; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 0 - 20 &deg;C / Inert atmosphere<br />3.1: pyridine; hydrogen fluoride / tetrahydrofuran / 7 h / 0 - 20 &deg;C / Inert atmosphere<br />4.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / 1 h / -78 &deg;C / Inert atmosphere<br />4.2: -78 - 20 &deg;C / Inert atmosphere<br />5.1: tert.-butyl lithium / diethyl ether; pentane / 0.08 h / -78 &deg;C / Inert atmosphere<br />5.2: 0.67 h / 0 &deg;C / Inert atmosphere<br />5.3: 3.5 h / 0 - 20 &deg;C / Inert atmosphere<br />6.1: 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; [bis(acetoxy)iodo]benzene / dichloromethane / 20 &deg;C / Inert atmosphere<br />7.1: n-butyllithium; chloro-trimethyl-silane; triethylamine; diisopropylamine / tetrahydrofuran; hexanes / -78 - 20 &deg;C / Inert atmosphere<br />7.2: 120 &deg;C / Inert atmosphere<br />8.1: methanol; diethyl ether; benzene / 1.5 h / 6 - 20 &deg;C / Inert atmosphere<br />9.1: pyridine; hydrogen fluoride / tetrahydrofuran / 24 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 8 steps<br /> </b>1.1: 1H-imidazole; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 0 - 20 &deg;C / Inert atmosphere<br />2.1: pyridine; hydrogen fluoride / tetrahydrofuran / 7 h / 0 - 20 &deg;C / Inert atmosphere<br />3.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / 1 h / -78 &deg;C / Inert atmosphere<br />3.2: -78 - 20 &deg;C / Inert atmosphere<br />4.1: tert.-butyl lithium / diethyl ether; pentane / 0.08 h / -78 &deg;C / Inert atmosphere<br />4.2: 0.67 h / 0 &deg;C / Inert atmosphere<br />4.3: 3.5 h / 0 - 20 &deg;C / Inert atmosphere<br />5.1: 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; [bis(acetoxy)iodo]benzene / dichloromethane / 20 &deg;C / Inert atmosphere<br />6.1: n-butyllithium; chloro-trimethyl-silane; triethylamine; diisopropylamine / tetrahydrofuran; hexanes / -78 - 20 &deg;C / Inert atmosphere<br />6.2: 120 &deg;C / Inert atmosphere<br />7.1: methanol; diethyl ether; benzene / 1.5 h / 6 - 20 &deg;C / Inert atmosphere<br />8.1: pyridine; hydrogen fluoride / tetrahydrofuran / 24 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / 1 h / -78 &deg;C / Inert atmosphere<br />1.2: -78 - 20 &deg;C / Inert atmosphere<br />2.1: tert.-butyl lithium / diethyl ether; pentane / 0.08 h / -78 &deg;C / Inert atmosphere<br />2.2: 0.67 h / 0 &deg;C / Inert atmosphere<br />2.3: 3.5 h / 0 - 20 &deg;C / Inert atmosphere<br />3.1: 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; [bis(acetoxy)iodo]benzene / dichloromethane / 20 &deg;C / Inert atmosphere<br />4.1: n-butyllithium; chloro-trimethyl-silane; triethylamine; diisopropylamine / tetrahydrofuran; hexanes / -78 - 20 &deg;C / Inert atmosphere<br />4.2: 120 &deg;C / Inert atmosphere<br />5.1: methanol; diethyl ether; benzene / 1.5 h / 6 - 20 &deg;C / Inert atmosphere<br />6.1: pyridine; hydrogen fluoride / tetrahydrofuran / 24 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1.1: zirconocene dichloride; diisobutylaluminium hydride / tetrahydrofuran; n-heptane / 1 h / 0 - 65 &deg;C / Inert atmosphere; Darkness<br />1.2: 0.25 h / -78 &deg;C / Inert atmosphere<br />2.1: tert.-butyl lithium / diethyl ether; pentane / 0.08 h / -78 &deg;C / Inert atmosphere<br />2.2: 0.67 h / 0 &deg;C / Inert atmosphere<br />2.3: 3.5 h / 0 - 20 &deg;C / Inert atmosphere<br />3.1: 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; [bis(acetoxy)iodo]benzene / dichloromethane / 20 &deg;C / Inert atmosphere<br />4.1: n-butyllithium; chloro-trimethyl-silane; triethylamine; diisopropylamine / tetrahydrofuran; hexanes / -78 - 20 &deg;C / Inert atmosphere<br />4.2: 120 &deg;C / Inert atmosphere<br />5.1: methanol; diethyl ether; benzene / 1.5 h / 6 - 20 &deg;C / Inert atmosphere<br />6.1: pyridine; hydrogen fluoride / tetrahydrofuran / 24 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;