Total synthesis of the marine alkaloid (-)-lepadin B

Abstract

An enantioselective total synthesis of (-)-lepadin B has been developed starting from (2S,4S)-2,4-O-benzylidene-2,4-dihydroxybutanal. The key steps in the synthesis include the use of an aqueous intramolecular acylnitroso Diels-Alder reaction to afford the trans-1,2-oxazinolactam and Suzuki cross-coupling reaction to elaborate the (E,E)-octadienyl unit.