Clay catalysis of the non-aqueous diels-alder reaction and the importance of humidity control

Article abstract of DOI:10.1016/0040-4039(91)80645-M

Unmodified kaolin clays are a simple and viable alternative to ferric ion-exchanged montmorillonites as catalysts for the normal electron demand Diels-Alder reaction. Water is the enemy: at 1 - 2 % levels, the stereoselectivity drops by a factor two or three.