1: 99 percent / (trimethylsilyl)ethoxyacetylene 2: 66 percent / NaH / tetrahydrofuran / 2 h / Ambient temperature 3: 88 percent / HgO(yellow), 20percent H2SO4 / tetrahydrofuran / 5 h / Heating View Scheme

With  potassium hydroxide in  ethanol; water 1 h;  Heating;