A novel series of functionalized cylopropanone hydrates will be synthesized. Earlier synthetic difficulties have been overcome by making use of a cyclic ketal in the starting ketene acetal. This permits fruitful reaction with diazoacetonitrile and ethyl diazoacetate yielding the corresponding cyclopropanone ketal nitrile and ester. Reduction with lithium aluminum hydride yielded the amine and alcohol respectively. These substances and their analogues will be used in the construction of a new series of enzyme inhibitor with the cyclopropanone hydrate as the active trapping agent. Potential inhibitors for a number of enzymes, including chymotrypsin, papain,converting enzyme, elastase and HMG-CoA reductase, are suggested. From the same set of precursors, an unusual all-carbon 1,3-dipole will be explored. It is proposed that such substances might be used in new, direct cyclopentanone and cyclopentenone annulation reactions. In addition, a new Beta-enolate equivalent will be developed from this series of protected cyclopropanones. Finally, the underlying mechanistic reasons behind the unusual stability of the cyclic versus the non-cyclic ketals of the cyclopropanones will be explored.
