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[摘要]:An efficient asymmetric synthesis of the potential antitumor agent (-)-gonioheptolide A derivatives is described. By employing an (S)-proline-catalyzed aldol reaction, the RAMP hydrazone a-alkylation methodology, and a diastereoselective reduction with zinc borohydride five stereocenters are established in the target compound. 4-epi-Methoxy-gonioheptolide A was obtained in ten steps in 15% overall yield and excellent diastereo- and enantiomeric excesses (de >= 95%, ee >= 99%). |
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