Divergent synthesis of thapsigargin analogs.

Thapsigargin (3) is a potent inhibitor of the SERCA-pump protein, with potential for application in a variety of medicinal areas. The efficient and scalable syntheses of thapsigargin (3) and nortrilobolide (2) have been disclosed previously. To demonstrate the modularity of the previous routes, three natural products (compounds 6, 13, 15) and four analogs (compounds 17-20) have been divergently prepared from a common building block featuring varied acyl chains at the C2, C3, and C8 positions. Biological tests revealed that all of the compounds prepared displayed promising activity profiles.