A tetracarbonyl Paal-Knorr approach to semicorrins

Innitzer, Anna; Mulzer, Johann.   

Heterocycles  (2009),  77(2),  873-886.

A semicorrin model system was prepared via a novel twofold Paal-Knorr type cyclization of a tetracarbonyl precursor which was obtained from an aldol reaction between virtually identical partners, readily available from one and the same precursor.