1.1: 100 percent / thionyl chloride / 1 h / Heating 2.1: n-Buli; iPr2NH / tetrahydrofuran / 0.5 h / 0 °C 2.2: tetrahydrofuran / -78 - 20 °C 3.1: TBAF / tetrahydrofuran; methanol / Heating View Scheme

1.1: thionyl chloride / toluene / 2 h / Inert atmosphere; Reflux 2.1: dichloromethane / 20 °C / Inert atmosphere 3.1: N,N,N',N,-tetramethylethylenediamine; tert.-butyl lithium / tetrahydrofuran / -78 °C / Inert atmosphere 3.2: 20 °C / Inert atmosphere 3.3: 20 °C / Inert atmosphere 4.1: manganese(IV) oxide; acetic acid / dichloromethane / 20 °C / Inert atmosphere 5.1: tetrahydrofuran / -78 °C / Inert atmosphere 5.2: Inert atmosphere 6.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme