Pyrrolidinones derived from (S)-pyroglutamic acid. Part 2. Conformationally constrained kainoid analogues

Novel conformationally constrained glutamate analogues are readily availabl e from (S)-pyroglutamic acid using a bicyclic lactam as a synthetic templat e; diastereocontrolled modification of the pyrrolidine ring using a sequent ial conjugate addition-substitution strategy permits access to several kain oid analogues in a versatile strategy. The pyrrolidinone ring conformation appears to be controllable by the nature of remote substituents on the hete rocyclic ring.