Scheme 1. Top: DFT proposed reaction paths for the aromatization of the Diels–Alder adduct formed by the reaction of dimethylfuran on methylpropiolate in presence of ZnCl2. The structures of the reagent, intermediates and products are displayed. Bottom: Structure and relative energies (E+ZPE) of all considered phenolic products. Relative energies (E+ZPE) are given in kcal mol−1 (as computed at the M062X/6-311++G(d,p) level of theory). Phenol 12b is coloured in gray to remind that no reaction route was found to lead to this product.
