sulfuric acid in butan-1-ol 7.5 h; Heating;

1: 61 percent / 25percent H2SO4 / butan-1-ol / 7.5 h / Heating 2: 91 percent / AcOH / H2O / 2 h / Ambient temperature View Scheme

Multi-step reaction with 3 steps 1: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 2.) THF, hexane, 0 deg C, 30 min2: 88 percent / Ac2O / heptane / 1 h / Heating3: 94 percent / tetrahydrofuran; diethyl ether / 0.5 h / 0 °C  

Multi-step reaction with 2 steps 1: 88 percent / Ac2O / heptane / 1 h / Heating2: 94 percent / tetrahydrofuran; diethyl ether / 0.5 h / 0 °C