1.1: sodium t-butanolate / N,N-dimethyl-formamide / 0 - 20 °C 2.1: trifluorormethanesulfonic acid / 1,2-dichloro-ethane / 0 - 20 °C 3.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 20 °C / Inert atmosphere 3.2: 80 °C View Scheme

1: sodium t-butanolate / N,N-dimethyl-formamide / 0 - 20 °C 2: trifluorormethanesulfonic acid / 1,2-dichloro-ethane / 0 - 20 °C View Scheme

1: sodium t-butanolate / N,N-dimethyl-formamide / 0 - 20 °C 2: trifluorormethanesulfonic acid / 1,2-dichloro-ethane / 0 - 20 °C 3: cesium fluoride / acetonitrile / 24 h / 20 °C View Scheme