Synthesis of (R)-(+)-3-(1-hydroxyethylidene)-1-(1-phenylethyl)piperidine-2,4-dione, novel Tetramic Acid Analogue

Herein, starting from (R)-(+)-α-methylbenzylamine, we report an efficient synthesis and full characterization of a new (R)-3-(1-hydroxyethylidene)-1-(1-phenylethyl)piperidine-2,4-dione, a new tetramic acid analogue. The key steps involved a non-classical Corey-Chaykovsky intramolecular cy-clization reaction to access the corresponding zwitterion, followed by a sequential desul-furization/reduction and condensation procedure. The key intermediate was obtained in 5 steps, and the desired product 7 with an overall 58% yield.