Abstract: Disclosed is a method for the preparation of norbornene and substituted norbornene compounds via a Diels-Alder reaction, in which a cyclic diene is reacted with an olefinic compound in order to prepare a norbornene compound. According to the invention a cyclic diene is gradually added to react with an olefinic compound, in order to keep the concentration of the cyclic diene in the reaction mixture as low as possible during the reaction. It is possible to obtain a very pure product, high yield, short reaction time and high concentrations of the exo diastereomer with the method of the invention.