摘要：

A new synthetic route for macrosphelides A, B, and E based on ring-closing metathesis (RCM) was established. The substrates for RCM could be synthesized starting from commercially available chiral materials, methyl (S)-lactate and methyl (S)- or (R)-3-hydroxybutyrate, in good overall yields. In the investigation of the key RCM step, it was found that the steric factor around the reaction site significantly affected the reaction rate of macrocyclization. A detailed account regarding this synthetic study is described herein.

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