New access to 4-aryl[2,2]paracyclophanes by high-pressure Diels–Alder reaction

[Display omitted] The first synthesis of novel 4-aryl[2,2]paracyclophanes based on the Diels–Alder reaction of 4-carbomethoxyethynyl[2,2]paracyclophane as the dienophile with methyl-1,3-butadienes is described. Activation of the Diels–Alder reactions by high-pressure (8kbar) in combination with the Lewis acid EtAlCl2 allows to obtain in good yield and total regioselectivity the cyclohexadienyl-paracyclophane cycloadducts that are converted to the corresponding aryl-paracyclophanes by DDQ oxidation.