Using cross-metathesis to couple L-phenylalanine to a macrocyclic lactam

Grubbs' second generation ruthenium catalyst was used to couple the amino acid l-phenylalanine to a 17-membered lactam, using cross-metathesis with an E-alkene favored in the process. The best coupling conditions gave the product in 48% yield. The reversibility of the process was also confirmed. Ring-closing metathesis was a key reaction used to form the macrocyclic lactam.