A two-step sequence for the conversion of heterocyclic imines to saturated and unsaturated polycyclic chlorinated ε-lactams is disclosed. In the first step, an acyl chloride addition followed by a substitution is used to achieve unsaturated methoxyamides. The final lactamization to two different classes of polycyclic ε-lactams via formation of a C–C bond is realized by the use of metal chlorides as Lewis acid and as a source of chloride. The potential of the ε-lactams in subsequent reactions is demonstrated by an elimination reaction.
Key words
heterocycles - imines - lactams - ring closure - ring contraction - Schiff bases