Comprehensive DFT Study on Site‐, Regio‐, and Stereoselectivity of Diels–Alder Reactions Leading to 5‐Hydroxybenzofurans
Diels–Alder reactions between the substituted furans 1a–1c and Danishefsky's diene (2), yielding 5-hydroxybenzofurans, were studied by density functional theory [B3LYP/6-31G(d) level] in benzene as solvent (SP/CPCM). The mechanistic details of these reactions, especially with respect to regio-, site-, and stereochemistry were analyzed in detail. Moreover, the extrusion of nitrous acid from the Diels–Alder cycloadducts and the formation of the aromatic products were also explained in order to give a total description of the complete domino processes.