Zur Einführung von Heteroatomen in die α-Stellungen von 9,10-Anthrachinon durch Diels-Alder-Synthese

Abstract

The problem of introducing hetero atoms into the α-positions of anthraquinone by diene synthesis has received little attention so far. It is briefly discussed for oxygen and chlorine containing dienes and 1,4-naphthoquinone as a dienophile. Properly substituted open chain 1,3-dienes are not well suited for this purpose because their adducts with 1,4-naphthoquinone have a strong tendency to lose the hetero atoms during the course of aromatization. This can be avoided by using five-membered cyclic 1,3-dienes as illustrated by the synthesis of three different anthraquinone derivatives containing chlorine in the α-positions.