Terpenoid-derived β-ketoesters: ring expansion of camphor with diazoacetate and a few transformations of homocamphor-3-carboxylate

Abstract

The synthesis of a racemic and non-racemic β-ketoester of the homocamphor series was performed in a two-step sequence via the formation of enol ethers using AlCl₃-promoted Büchner–Curtius–Schlotterbeck ring expansion of rac- or R(+)-camphor as the starting material. A few types of chemical transformations were investigated with stereochemical implications. The synthetic potential of the synthesized β-ketoester has been demonstrated in several reactions, including diastereoselective epimerization, alkylation, functionalization, oxidative cleavage, and reactions with binucleophilic reagents or HN₃.