Rhodium‐Catalyzed [4+3] Cycloaddition to Furans: Direct Access to Functionalized Bicyclo[5.3.0]decane Derivatives

An efficient method to directly access the bicyclo[5.3.0]decane core was achieved by rhodium-catalyzed reaction of a novel donor-acceptor cyclopentenyl diazocarboxylate with a variety of furans. As this motif is commonly found within bioactive antitumor natural products, selected systems were further manipulated and evaluated against cancer cell lines sensitive to protein kinase C (PKC) activation. A cyclic donor-acceptor diazo compound was synthesized for the first time, facilitating direct access to the bicyclo[5.3.0]decane motif, which is commonly seen in a number of prominent natural products active against cancer. Some examples were evaluated against various PKC cancer cell lines.