Organic Chemistry

A concise total synthesis of phytotoxic radulanin A facilitated by the photochemical ring expansion of a 2,2-dimethylchromene in flow



The radulanins are biologically active bibenzyl natural products featuring a synthetically challenging 2,5-dihydro-1-benzoxepine core. In contrast with previous reports exhibiting lengthy strategies, we demonstrate the shortest synthesis of radulanin A to date, featuring a largely unexplored photochemical ring expansion reaction of a 2,2-dimethylchromene precursor. This work was adapted to a continuous flow setup for larger scale preparation, in view of biological investigations into the herbicidal properties of this natural product.


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Supplementary material

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Supporting information
Supporting tables and schemes Experimental procedures Copies of NMR spectra