Synthesis of Acyclic Polycarbonyl Compounds via Ozonolysis of Cyclohexa-1,4-dienes

Cobalt-catalyzed Diels-Alder reaction of 2-(trimethylsiloxy)buta-1,3-dienes with alkynes gives substituted cyclohex-3-en-1-ones that were converted into polycarbonyl derivatives upon ozonolysis. Wittig olefination of ketoaldehydes gave unsaturated polycarbonyl derivatives or alternatively the ketoaldehydes were reacted with primary and secondary amines to give vinylogous amides. 2,7-Didiazo-1-phenylnonane-1,3,6,8-tetraone underwent double diazo-transfer reaction at the 1,3-dicarbonyl subunits by rhodium-catalyzed cyclization to give the cyclohex-2-ene-1,4-dione backbone.