Microwave assisted pericyclic reactions in cascade to construct decalin frameworks possessing quaternary centers.scope and limitations

摘要

The synthesis of decalin skeletions possessing quaternary carbon centers at c9 usign the tandem oxy-Cope/ene/claisen si described.The degree of substitution at he terminal olefin plays an important role in determining the pathway of the reaction.In the case of 1,2-divinylcyclohexanol having a 1,2-disubstituted allyl ether,the corresponding decalin skeletions were obtained in good yeilds in the case of trisubstituted allyl ehters,decalin products resulting from a radical 1,3-shift were isolated.the microwave irradition of 1,2-divinylcyclohexanol propargyl ethers produced tetracyclic acetal sesquiterpenes via an oxy-Cope/ene/Clasisen/5-exo dig cyclization reaction in high disatereoselectivity.The scope and limitation of the method is described.