Total Synthesis of Rhizopodin Enabled by a Late-Stage Oxazole Ring Formation Strategy.

Actin stabilizers that are capable of interfering with actin cytoskeleton dynamics play an important role in chemical biology. Rhizopodin, a novel actin stabilizer, affects the actin cytoskeleton at nanomolar concentrations and exhibits potent antiproliferative activities against a range of tumor cell lines with IC50 values in the low nanomolar range. Herein, we report the total synthesis of rhizopodin based on a late-stage oxazole ring formation strategy, whose success demonstrates the feasibility of late-stage oxazole ring formation in the synthesis of complex oxazole containing natural products. Other features of the synthesis include a Nagao aldol reaction, a Suzuki coupling, a Yamaguchi esterification, a modified Robinson-Gabriel synthesis of the oxazoles, and a bidirectional Ba(OH)2-mediated Horner-Wadsworth-Emmons (HWE) reaction.