hydrogenchloride 0.5 h; Heating;

1.1: NaOEt / ethanol 1.2: ethanol 2.1: NaH / tetrahydrofuran 2.2: aq. p-TsOH / acetone View Scheme

1.1: lithium N,N-diisopropylamide / hexane; tetrahydrofuran / 0.83 h / -75 °C 1.2: 100 percent / hexane; tetrahydrofuran; toluene / 0.5 h / -75 °C 2.1: 99 percent / 1M aq. HCl / 0.5 h / Heating View Scheme

1: With sodium hydride in tetrahydrofuran 2: With toluene-4-sulfonic acid in acetone

1: With sodium hydride in tetrahydrofuran 2: With toluene-4-sulfonic acid in acetone