SYNTHESIS OF NOVEL HETEROCYCLES RELATED TO THE DYNEMICIN-A RING SKELETON

Studies directed towards the construction of the CDE ring framework of dynemycin A (1) are reported. A series of quinoline based dienophiles containing an activating group (e.g. 5, Scheme 1), reacted with acycl ic dienes (e.g. 4, Scheme 1) in a Diels-Alder fashion under increased pressure to afford a variety of heterocyclic systems related to the CD E skeleton of dynemycin A. Reaction of dienophile 15 with cyclic diene 29 led to the novel hetereocycle 34 whereas attempted decarbonylation of 41 led to a novel rhodium-promoted intramolecular carbonylation of the terminal acetylene furnishing compound 43.