Expedient Organocatalytic Syntheses of 4-Substituted Pyrazolidines and Isoxazolidines.

The efficient organocatalytic synthesis of heterocyclic systems of biological relevance is a subject of growing interest. We have found that the pyrrolidine/benzoic acid-catalyzed reaction of α-substituted propenals such as methacrolein, 2-benzylpropenal and 2-(-hexyl)propenal with activated hydrazines takes place in very good yields (83%-99.6%) under very mild conditions to afford 4-substituted pyrazolidin-3-ols (as diastereomer mixtures); subsequent oxidation with PCC affords the corresponding-4-substituted-3-pyrazolidinones in essentially quantitative yields.

Reversed phase High Performance Liquid Chromatography used for the physicochemical and thermodynamic characterization of piceatannol/β-cyclodextrin complex.

Piceatannol is one of resveratrol derivatives having health promoting potential. However, its low water-solubility and bioavailability could limit its use in both food and pharmaceutical fields. The aim of this work is the study of piceatannol complexation by β-cyclodextrin (β-CD) in aqueous media.