Synthesis of the Antibiotic (R)-Reutericyclin via Dieckmann Condensation

(R)-Reutericyclin ((R)-1), a bactericidal, amphiphilic natural product with a trisubstituted tetramic acid moiety, was prepared in four steps from D-leucine in an overall yield of 24%. The chiral heterocyclic portion of 1 was synthesized by Dieckmann cyclization of ethyl N-(acetoacetyl)leucinate (7), and the resulting pyrrole derivative 8 was N-acylated with (E)-dec-2-enoyl chloride in the presence of BuLi at − 70° (Scheme 2). This new procedure is straightforward and allows the synthesis of both antipodes of reutericyclin in an enantiomeric excess (ee) of ca. 80%.