Medium??ring lactones are challenging targets of interest either as intermediates or as bioactive compounds.1 View all references Indeed, many natural products have been described with medium?? to large??ring lactones.24. Rousseau , G. 1995. Medium ring lactones. Tetrahedron, 51: 2777–2849. [CrossRef], [Web of Science ®] View all references However, they are hardly prepared chemically, even by the most obvious ring??forming lactonization.3 View all ...