Chemoselective nucleophilic attack on N-acyl derivatives of (S)-ethyl 4,4-dimethyl pyroglutamate (DMPG).

[reaction: see text] Heteronucleophiles and C-nucleophiles chemoselectively react with N-acyl (S)-ethyl 4,4-dimethyl pyroglutamate (DMPG) affording esters, amides, and ketones in high yield. The intramolecular process allows the stereoselective formation of beta-hydroxy acids likely by formation and ring opening of the corresponding beta-lactones