1.1: 1-chloroethyl chloroformate / CH2Cl2 / 2 h / Heating 1.2: MeOH / 1 h / Heating 1.3: 80 percent / aq. KOH / methanol; dioxane / 16 h / 18 °C 2.1: 99 percent / TBAF / Pd2(dba)3*CHCl3 / tetrahydrofuran / 19 h / 20 °C View Scheme

tetrabutyl ammonium fluoride in tetrahydrofuran 18 - 20 h; Product distribution / selectivity;