Total Syntheses of (−)‐Transtaganolide A, (+)‐Transtaganolide B, (+)‐Transtaganolide C, and (−)‐Transtaganolide D and Biosynthetic Implications

‘Dibal'lin’ on a budget: The enantioselective total syntheses of transtaganolides A–D are rapidly achieved by a highly diastereoselective Ireland–Claisen/Diels–Alder cascade reaction of an enantioenriched geraniol derivative (see scheme). Based on X-ray diffraction data, the absolute configuration of these metabolites is established and discussed within the context of existing biosynthetic hypotheses.