1: 54 percent / KOH; pig-kidney acylase I; H2O / 144 h / 37 °C 2: 91 percent / thionyl chloride / -10 - 20 °C 3: 98 percent / sodium carbonate / dioxane; H2O / 0 - 20 °C 4: 83 percent / triphenylphosphine; N-bromo-succinimide / tetrahydrofuran / 0 - 20 °C 5: 100 percent / sodium sulfite; H2O / dioxane / 1 h / 100 °C 6: 76 percent / subtilisin; aq. NaOH / aq. phosphate buffer / 4 h / 20 °C View Scheme

1: 99 percent / tetrahydrofuran 2: 83.5 percent / BF3-etherate, tetraethylammoniumbromide / CHCl3 / 10 h / Heating 3: 67 percent / 6 h / Heating View Scheme