N-Silylated allylamines 1 are effectively transformed into methyl cyclopropanecarboxylates 2 by methyl diazoacetate under Rh,(OAc), catalysis. Derivatives 2a and 2b are smoothly converted into trans-substituted amino acids 6a and 6b, re-spectively, and to bicyclic y- lactams 5a and 5b. The pharmacologically interesting y-aminobutyric acid (GABA) analogue trans-6a is now available in few steps. Photochemical and thermal Fe (CO),-induced ...