Lactams, preparation from cyclopropanes

The asymmetric syntheses of carnosadine (lS,2S)-74 [101] and of its protected derivatives as conformationally constrained surrogates for arginine have also been reported [102]. Different 2-substituted 1-aminocyclopropanecarboxylic acids have also been prepared by azidation of optically active 2-chloro-2-cyclo-propylideneacetates [103] and from the cyclopropanation of chiral bicyclic lactams [104]. 

---