Synthesis of the C1‐C18 fragment of Neaumycin B

Abstract

AbstractStereoselective synthesis of the C1–C18 fragment 2 of Neaumycin B (1), 28‐membered macrolide compound with 19‐chiral centers and 6,6‐spiroketal structure, has been described. Brown syn‐crotylation and olefin metathesis reaction were used as key steps from (R)‐roche ester in the synthesis of C8–C18 fragment 3. C1–C7 fragment 4 was constructed from 1,3‐propanediol using diastereoselective allylation, syn‐aldol reaction, and olefin metathesis reaction as key steps. Finally, NHK reaction and (S)‐CBS reduction as key steps led to the of synthesis of C1–C18 fragment 2 of Neaumycin B (1).