Asymmetric intramolecular cyclopropanation. Synthesis of conformationally constrained aminocyclopropane carboxylic acids

Conformationally constrained amino acids are useful for the construction of peptidomimetics with certain beneficial features for medicinal applications. In this paper we discuss some of the features which make these non-natural amino acids desirable candidates, and present a facile approach to the title compounds. Metal-catalyzed asymmetric induction provides a straightforward entry into the title compounds. The successes and shortcomings of this approach are discussed, and plausible rationalizations for the observed stereochemical control are presented.