Application of tandem Ugi reaction/ring-closing metathesis in multicomponent synthesis of unsaturated nine-membered lactams

A new straightforward entry into unsaturated nine-membered lactams of potential use as external reverse turn inducers was developed. It is based on an Ugi multicomponent reaction using two unsaturated substrates, followed by highly stereoselective ring-closing metathesis (RCM). The synthesis of a nine-membered secondary lactam by RCM is reported for the first time.