The synthesis of multifunctional spirocycles was achieved from common cyclic carboxylic acids (cyclobutane carboxylate, cyclopentane carboxylate, l-proline, etc.). The whole sequence included only two chemical steps-synthesis of azetidinones, and reduction into azetidines. The obtained spirocyclic amino acids were incorporated into a structure of the known anesthetic drug Bupivacaine. The obtained analogues were more active and less toxic than the original drug. We believe that this discovery will lead to a wide use of spirocyclic building blocks in drug discovery in the near future.

A new spirocyclic amino acid for drug discovery, a surrogate for l‐proline/pipecolic acids, is described. The synthesis of multifunctional spirocycles starts from the commonly available cyclic carboxylic acids, for example, cyclobutane carboxylate, cyclopentane carboxylate, and l‐proline. The whole sequence includes only two chemical steps: synthesis of azetidinones and reduction into azetidines. The obtained spirocyclic amino acids were incorporated into a structure of the known anesthetic drug bupivacaine. The obtained analogues were more active and less toxic than the original drug. We believe that this discovery will lead to the wide use of spirocyclic building blocks in drug discovery in the nearest future. More information can be found in the Communication by P. K. Mykhailiuk et al. on page 5444.