Identification of thiazolidines in guava: stereochemical studies

Volatile compounds from guava (Psidium guajava L.) were extracted using dic hloromethane. 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 frui ts. The chemical synthesis of the reference compounds and other analogues a llowed the further comparison with the guava extracted thiazolidines. The a bsolute configuration of the cis/trans isomers was determined by nuclear ma gnetic resonance (H-1-NMR) and by nuclear overhauser enhancement (2D NMR NO ESY). Copyright (C) 2001 John Wiley & Sons, Ltd.