A concise synthesis of pinellic acid using a cross-metathesis approach

A new enantioselective synthesis of pinellic acid, a trihydroxy unsaturated fatty acid exhibiting oral adjuvant activity for nasally administered influenza vaccine, has been accomplished using a cross-metathesis reaction between two terminal olefin intermediates as the key step. This synthesis is the shortest to date, furnishing pinellic acid in 17% overall yield via only seven steps from a readily available known dihydroxy ester.