Abstract: | A hetero Diels‐Alder reaction with inverse electron demand between 4‐hydroxycoumarin, aromatic aldehydes and electron‐rich alkenes yielded a multitude of 2,4‐disubstituted 3,4‐dihydropyranocoumarins. This route opened an easy access to coumarin anticoagulants and provided a library of pyranocoumarin derivatives. |