Identification of thiazolidines in guava: stereochemical studies

Volatile compounds from guava (Psidium guajava L.) were extracted using dichloromethane. Among these volatile compounds, methyl 2‐methyl‐thiazolidine‐4‐(R)‐carboxylate (cis and trans) and the ethyl 2‐methyl‐thiazolidine‐4‐(R)‐carboxylate (cis and trans) could be identified for the first time in fruits. The chemical synthesis of the reference compounds and other analogues allowed the further comparison with the guava extracted thiazolidines. The absolute configuration of the cis/trans isomers was determined by nuclear magnetic resonance (1H‐NMR) and by nuclear overhauser enhancement (2D NMR NOESY). Copyright © 2001 John Wiley & Sons, Ltd.