formation of 2,3-dioxo-2,3-dihydrofurano[4,5-d][2.2]paracyclophane (8) as a product of an unusual cooperative C- and O-acylation was observed. Replacement of the OH group in the substrate for OCH3 (compound 18) changes the regioselectivity of the oxaloylation, which now occurs with formation of a para-substituted α-diketone 19. A novel technique for the synthesis of 4-formyl-5-hydroxy[2.2]paracyclophane