Stereochemical studies. Part 86. Saturated heterocycles. Part 81. Preparation of new thiouracils via retrodiene decomposition of methylene-bridged quinazolone thiones

Abstract

endo- and exo-Norbornene (1) and (3) and norbornane (2) and (4) amino acids and isothiocyanates give methylene-bridged 2-thioxohexahydro-(10) and (11) and octahydro-(12) and (13)-quinazolin-4-ones. Compounds (10) and (11) decompose in a retro-Diels-Alder reaction when heated to melting, to give new 3-substituted thiouracils (14a–e); no convenient general suitable method was previously known for the preparation of these compounds.