M. Essayed et al., AN ASYMMETRIC-SYNTHESIS OF NOVEL AMINOCYCLOPROPYL CARBOXYLIC-ACIDS (ACC), Journal of the Chemical Society, Chemical Communications, (2), 1995, pp. 141-142
Cyclopropanation of chiral bicyclic lactams 2 followed by removal of t
he chiral auxiliary and a Curtius rearrangement leads to the title com
pounds in > 99% e.e.