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

[2.2]Paracyclophane (7.60 g, 36.4 mmol, 1.00 equiv.) was dissolved in dichloromethane (50 mL) was cooled to –50 °C. A solution of aluminum trichloride (8.51 g, 64.0 mmol, 1.75 equiv.) and acetyl chloride (4.95 g, 63.0 mmol, 1.73 equiv.) in dichloromethane (50 mL) was slowly added. After 3h at –20 °C, the solution was poured on ice and stirred until discoloration. The phases were separated, and the aqueous layer was acidified with hydrochloric acid (12 M in water), then extracted with dichloromethane (3 x 25 mL). The organic phase was then extracted with sodium hydroxide (1 M aq. solution, 3 x 50 mL). The combined organic layers were washed with sodium chloride (sat. aq. solution, 100 mL), dried over sodium sulfate and the solvent was removed under reduced pressure.