Total Syntheses and Absolute Stereochemical Correction of Negundin B, Vitexin 1, and Vitexin 6

A highly adaptable asymmetric synthetic route toward dihydronaphthalene lignans was developed, with its application to the syntheses of negundin B and vitexin 1/6 described herein. This developed pathway proceeded through an enantioselective aldol reaction to establish the contiguous stereocenters present in the final structures with subsequent functional group transformations yielding (−)-negundin B and (−)-vitexin 1/6. The enantioselective synthesis of vitexin 1/6 allowed the correction of absolute configuration, which has been widely incorrectly reported.