1: 97 percent / aq. KOH / dioxane / 1 h 2: 1-chloro-2,N,N-trimethylprop-1-en-1-ylamine / tetrahydrofuran / 40 h / -18 °C 3: 0.16 g / Fe(acac)3 / tetrahydrofuran / 0.5 h / 0 °C View Scheme

Multi-step reaction with 2 steps 1: 71 percent / tetrahydrofuran2: 77 percent / NaH / tetrahydrofuran  

Multi-step reaction with 3 steps 1: 1N KOH2: MeLi / -78 deg C to r.t.3: 58 percent / 1.) LiN(SiMe)3; 2.) ZnCl2 / tetrahydrofuran / -78 °C