boron trifluoride diethyl etherate T=60 - 70°C; 16 h; Yield given;

1: BF3*OEt2 / 16 h / 60 - 70 °C 2: 1.) lithium diisopropylamide, HMPA, 2.) methanol / 1.) THF, n-hexane, -78 deg C, 2 h, 2.) -78 deg C, 15 min 3: 1.) lithium diisopropylamide / 1.) THF, -78 deg C, 2 h, 2.) a) -78 deg C, 30 min, b) 0 deg C, 1 h 4: 1.) 1 M n-Bu4NF, 2.) H2O / 1.) THF, 0 deg C, 1 h, 2.) 15 min View Scheme

1: BF3*OEt2 / 16 h / 60 - 70 °C 2: 1.) lithium diisopropylamide, HMPA, 2.) methanol / 1.) THF, n-hexane, -78 deg C, 2 h, 2.) -78 deg C, 15 min View Scheme

sodium hydroxide 1.) THF, 25 deg C, 15 h, 2.) reflux, 24 h; Yield given. Multistep reaction;