Search for highly efficient, stereoselective, and practical synthesis of complex organic compounds of medicinal importance as exemplified by the synthesis of the C21-C37 fragment of amphotericin B.

Highly stereoselective: A highly efficient, stereoselective and practical synthesis of the C21-C37 fragment of amphotericin B was realized in 25 % overall yield in eight longest linear steps from commercially available ethyl (S)-3-hydroxybutyrate by using Fráter-Seebach alkylation, Brown crotylboration, Negishi coupling, Heck reaction, and Horner-Wadsworth-Emmons (HWE) olefination as key steps (see diagram).