1: 1) BuLi / 1) THF, hexane, -78 deg C, 1 h, 2) THF, -78 deg C, 2 h, then rt, 15 h 2: BF3*OEt2 / tetrahydrofuran / Ambient temperature View Scheme

1: 1) BuLi / 1) THF, hexane, -78 deg C, 1 h, 2) THF, -78 deg C, 2 h, then rt, 15 h 2: 1) BuLi / 1) THF, hexane, -78 deg C, 1 h, 2) THF, -78 deg C, 2 h, then rt, 15 h 3: BF3*OEt2 / tetrahydrofuran / Ambient temperature View Scheme

1: 1) BuLi / 1) THF, hexane, -78 deg C, 1 h, 2) THF, -78 deg C, 2 h, then rt, 15 h 2: BF3*OEt2 / tetrahydrofuran / Ambient temperature View Scheme

boron trifluoride diethyl etherate in tetrahydrofuran Ambient temperature; Title compound not separated from byproducts;

1.) THF, -78 deg C, 2.) THF, room temp., 18 h; Yield given. Multistep reaction;