A total synthesis of brevisamide, a marine monocyclic ether amide isolated from the dinoflagellate Karenia brevis, has been achieved in 18 steps starting from 4-(benzyloxy)butanol. The synthesis involves oxiranyl anion coupling between an epoxy sulfone and a triflate, intramolecular etherification of a hydroxy-bromoketone, diastereoselective introduction of the axial methyl group by hydroxyl-directed hydrogenation of an exocyclic olefin, and installation of an acetamide side chain by nucleophilic substitution of an N-acetyl carbamate. The dienal side chain is assembled using a Horner-Wadsworth-Emmons reaction to complete the synthesis.

Die Umsetzung von 2,3‐Epoxy‐isoflavon (I) mit primären Aminen (II) ergibt die Phenole (III).

No abstract