Neolaxiflorin L (NL) is a low-abundant Isodon 7,20-epoxy-ent-kuarenoid and was found to be a promising anticancer drug candidate in our previous study. In order to study its structure−activity relationship (SAR), a diversity-oriented synthetic route toward two libraries of (±)-NL analogs, including analogs containing different functionalities in the same 7,20epoxy-ent-kuarene skeleton and analogs with skeletal changes, has been developed. The results of this total synthesis-enabled SAR successfully led to a bioactive alkyne-tagged NL derivative, which could be a useful probe for proteomics studies.