| It has been previously demonstrated that [(eta6 -benzyl acetoacetamide)RuCp][PF6] complexes will undergo a general reaction sequence resulting in the formation of spirocyclic products. These products are structurally similar to a number of naturally occurring alkaloids, and may serve as useful building blocks in their synthesis. It has been found that the spirocycle product may also be obtained as the result of coupling either an intramolecular Horner-Wadsworth-Emmons reaction or an intramolecular Baylis-Hillman reaction with arene-ruthenium chemistry. The Horner-Wadsworth-Emmons spirocyclization reaction is compatible with a wide variety of aldehydes, including aldehydes that are sterically encumbered, conjugated, and highly functionalized. The Baylis-Hillman spirocyclization reaction is efficient with unsubstituted benzyl acrylamides; however, substituted acrylamides react with diminished yield.;Both reaction sequences were investigated in connection with their compatibility with different removable amide protecting groups and their ability to form spirocyclic products in acceptable yields. This was completed using an arene with a dioxolane fused ring in an attempt to construct the 5,11-methanomorphanthridine framework. Construction of this ring system was not achieved; however, it was demonstrated that either a Boc group or an allyl/propenyl group effectively serves as removable amide protecting group. |
