Total synthesis of (2S,3S,4R)-plakoridine A

The β-amino ester 6 is synthesized via the diastereoselective Michael addition of the lithium amide derived from amine 5 to methyl (E)-2-hexenoate. This ester is converted to the pyrrolidinone 8 via an aldol condensation/deprotection/cyclization. Transformation of the lactam 8 into thiolactam 11 followed by Eschenmoser sulfide contraction provides (2S,3S,4R)-plakoridine A.