Short-RInChIKey=SA-FUHFF-UHFFFADPSC-RDUGGFZJQY-UHFFFADPSC-NUHFF-NUHFF-NUHFF-ZZZ

2-(4-[2.2]Paracyclophanyl)lactic acid methyl ester (1.95 g, 6.28 mol, 1.00 equiv.) was dissolved in dry dichloromethane (20 mL). Boron trifluoride diethyl etherate (48% w/w in diethyl ether, 4.85 mL, 18.9 mmol, 3.00 equiv.) was added. After 15 min, water (40 mL) was added. The phases were separated and the aqueous phase was extracted with dichloromethane (2 x 20 mL). The combined organic layers were washed with sodium hydrogen carbonate (sat. aq. solution, 2 x 30 mL), then dried over sodium sulfate and the solvent was removed under reduced pressure.