Total Synthesis of (−)‐Laulimalide: Pd‐Catalyzed Stereospecific Ring Construction of the Substituted 3,6‐Dihydro[2<i>H</i>]pyran Units

Abstract

The potent anticancer agent (−)-laulimalide (1) was prepared through a versatile method that should allow access to other marine natural products. Key steps included a Pd-catalyzed 1,3 chirality transfer of an allylic alcohol. The syn-SN2′-like processes occur stereospecifically in either 6-endo-trig or 6-exo-trig fashion to give the desired 3,6-dihydro[2H]pyran rings (see scheme).