This research includes two parts: methodology study of metal-mediated reactions, and applications of the methodology in natural product synthesis Part one: Methodology study. Allene aryl delta-lactones were conveniently synthesized through the reaction of various aldehydes with (o-carboxyaryl)propargyl bromide mediated by indium in aqueous ethanol Part two: Natural product syntheses. The epimer of 8,10-di-O-methyl bergenin was synthesized from a gallic acid derivative and D-arabinose through an aqueous indium-mediated formation of aryl delta-lactone in a critical step. The application of this indium method and some new strategies to the total synthesis of (+)-bergenin and its derivatives are still under investigation
