Stereoselective Photochemistry of Substituted Chalcones in Solution and their Antioxidant Activities

Abstract

Three new δ-truxinic type cyclobutanes [(1β,2α)-di-(4-ethylbenzoyl)-(3β,4α)-di-(4-methoxyphenyl) cyclo butane (4), (1β,2α)-di-(4-nitrobenzoyl)-(3β,4α)-di-(4-ethylphenyl) cyclobutane (5), and (1β,2α)-di-(4-ethylbenzoyl)-(3β,4α)-di-(4-ethylphenyl) cyclobutane (6)] have been prepared by stereoselective photodimerisation of the corresponding chalcone monomers (1-3) in solution. NMR and MS of the dimers are discussed. The precursor chalcones and the dimeric products showed antioxidant activities to different extents with respect to the individual compounds as well as to the antioxidant methods used.