Oxidative Coupling of â‐O‐4′ Dilignol Models Leading to Polycyclic Products with Rare Interlignol Linkages

Abstract

Our capability to utilize lignin as ar enewable resource has been continuouslye xpanding thanks to the information acquired through in-depth studies with various model compounds. Herein, efficient routes were devised to assemble biomass-derived building blocks for functionalized â-O-4' dilignol models. Oxidative coupling of these dilignols with hypervalent iodine(III) reagents led to two series of highly fused polycyclic products,dibenzo [b,d]oxepine and 2,7-dioxabicyclo[3,3,1]nonane derivatives. These products contain rare interlignol CÀCa nd CÀOl inkages and are otherwise difficult to synthesize. Preliminary studies suggested that some of these products had moderate anticancer activity.