Timed Diels-Alder reactions
In this paper a unique approach to the synthesis of polycyclic ring systems is disclosed. The approach features an intermolecular Diels-Alder reaction followed by an intramolecular Diels-Alder reaction where the regiochemistry of addition is controlled by substituents on the bisdiene and bisdienophile. This methodology has been applied to the synthesis of the fluorenone ring system.
Reprinted (adapted) with permission from Journal of the American Chemical Society, 102(6); 1974-1977. Doi: 10.1021/ja00526a036. Copyright 1980 American Chemical Society.