First total synthesis of Ternatusine A from D-allal

Ternatusine A has been synthesised in a highly diastereoselective manner starting from a readily available D-allal. It is a novel approach for the Ternatusine A, which is a natural product isolated from the rοοts οf <i>Ranunculus ternatus</i>. An intramolecular 1,3-dipoar cycloaddition of azomethine ylide generated <i>in situ</i> from C2-formyl-D-allal and ethyl <i>N</i>-benzyl glycinate, is a key step to construct the pyrrole core structure of the Ternatusine A. The carboxylic acid directed transition metal-catalysed C-H functionalization of pyrrole at C3 position is another notable feature of this process.