A facile synthesis of 3-aryl pyroglutamic acid. Facile synthesis of baclofen and chlorpheg

A facile synthesis of 3-aryl pyroglutamic acids via stepwise [3+2] annulation and desulfonated hydrolysis is reported. Base-induced coupling/cyclization reactions of α-sulfonylacetamide with various β-functional groups of (Z)-2-bromoacrylates yielded three contiguous chiral centers on the polysubstituted pyroglutamates system with trans–trans orientation in a one-pot synthesis. This facile strategy was used to synthesize amino acid derivatives baclofen and chlorpheg.