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 anoverall yieldof 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° (Scheme2). This new procedure is straightforward and allows the synthesis of both antipodes of reutericyclin in anenantiomeric excess (ee) of ca. 80%.