Optically Active Sulfoxides from 2(5<i>H</i>)-Furanone and Monoterpene Alcohols: Synthesis, Structure, and Antibacterial Activity

Abstract

A series of optically active 5(S)-(l-bornyloxy)- and 5(S)-(l-menthyloxy)-2(5H)-furanones with an arylthio group at the C(4) position of the γ-lactone ring was synthesized and studied for its oxidation reactions with various reagents. Novel 2(5H)-furanone sulfoxides were obtained as mixtures of two diastereoisomers through the oxidation of arylthioethers with m-chloroperbenzoic acid (m-СРВА) or hydrogen peroxide in acetic acid. Individual stereoisomers of these sulfoxides were isolated using recrystallization and high-performance liquid chromatography (HPLC) and characterized by IR and NMR spectroscopy. The molecular structures of eight stereoisomerically pure compounds were confirmed by X-ray diffraction (XRD) analysis. The antibacterial activity of the novel sulfoxides against Staphylococcus aureus and Escherichia coli was assessed, with a number of compounds found to inhibit bacterial growth and biofilm formation in S. aureus.

Keywords

• 2(5h)-furanones
• lactones
• sulfoxides
• oxidation
• stereochemistry
• optical activity
• antibacterial activity
• x-ray diffraction analysis