1: 1.) lithium diisopropyl amide; 2.) boron trifluoride etherate / 1.) THF, hexane, -78 deg C, 25 min; 2.) -95 to -40 deg C, 1.5 h 2: trifluoroacetic acid / CH2Cl2 / 1 h / Ambient temperature View Scheme

n-butyllithium; boron trifluoride diethyl etherate in tetrahydrofuran; hexane T=-78°C;

n-butyllithium; boron trifluoride diethyl etherate 1.) 20 min, -78 deg C, THF/n-hexane; 2.) 30 min, -78 deg C, THF; Yield given. Multistep reaction;

n-butyllithium; boron trifluoride diethyl etherate in tetrahydrofuran; hexane T=-78°C;