Meaning of Diels-Alder reaction

Diels'-Al'der reac"tion

Pronunciation: (dēlz'äl'dur), [key]
— Chem. Chem.
  1. the reaction in which a conjugated diene combines with a double or triple bond of a given compound to form a ring of six carbon atoms.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.