Sequential Alkene Isomerization and Ring-Closing Metathesis in Production of Macrocyclic Musks from Biomass

We report successful utilization of sequential alkene isomerization and ring‐closing metathesis of dec‐9‐enoic acid based dienes in synthesis of macrocyclic lactones that possess a strong scent of musk. This catalytic sequence was essential to trim the chain length of starting dienes to yield macrocycles of the right size. Dec‐9‐enoic acid is conveniently obtainable from oleic esters by Ru‐catalysed ethenolysis.