ChemInform Abstract: CONDENSATION OF 3‐CARBETHOXYCOUMARIN WITH KETONES IN THE PRESENCE OF AMMONIUM ACETATE OR AMINES

Abstract

Die Titelreaktion des Cumarins (I) mit den Ketonen (II) liefert die Benzoxazocine (IV), bei 170°C entstehen dagegen mit den entsprechenden Ketonen und Aminen oder NH4‐acetat die Pyranopyridine (V).

Diastereoselective Synthesis of Methanopyridoxazocinones

“…This route was first reported by Boehm who heated coumarin-3-carboxylic acid and para-substituted anilines in acetone under reflux for two days followed by decarboxylation. 12 Several groups have since used substituted 3-carboxyl, 13 3-carbethoxy, 14,15 3-acetyl [16][17][18] and 3-carboxamide 19 coumarins as starting materials. The mechanistic features of the reaction along with stereochemical outcomes were discussed recently by Deredas and co-workers.…”