Structures of Hemi‐Curcuminoids in the Solid State and in Solution

Abstract

AbstractHemi‐curcuminoids are derivatives of the antioxidant radical scavenger curcumin in which one styryl moiety is missing but the β‐diketone functionality is maintained. Five such derivatives have been prepared, and the X‐ray molecular structures for all of them have been determined. The tautomerism of the five compounds has been studied by NMR in the solid state and in solution. An enol–enol proton transfer barrier has been determined.