1.1: sodium hydroxide / water 2.1: tert.-butyl lithium; N,N,N',N,-tetramethylethylenediamine / tetrahydrofuran; n-heptane / |Molecular sieve; |Inert atmosphere; |Large scale 3.1: cyclohexane; toluene / 0.75 h / -78 °C 4.1: sodium iodide; chloro-trimethyl-silane / acetonitrile / 1 h / 20 °C 4.2: 3 h / 95 °C View Scheme

1.1: sodium hydroxide / water 2.1: sec.-butyllithium; N,N,N',N,-tetramethylethylenediamine / cyclohexane / 0.75 h / -78 °C 2.2: 0.75 h / -78 °C 3.1: cyclohexane; toluene / 0.75 h / -78 °C 4.1: methanesulfonic acid / dichloromethane / 5 h / |Reflux; |Large scale View Scheme