1. Rapid, Controlled Assembly of Polyenes
for Studying Pericyclic Reaction Cascades
David A. Vosburg, Department of Chemistry, Harvey Mudd College
Pericyclic reactions are among the most powerful transformations in organic chemistry, and they are even more impressive when they occur in tandem. Outstanding examples of pericyclic reaction cascades are found in the biosyntheses of the endiandric acids, a family of cyclic polyketides isolated from the Australian plant Endiandra introrsa (Lauraceae). Inspired by the cascades of cyclizations in the biogenesis of these natural products, we are using synthetic and computational approaches to study the selectivity and scope of these reaction cascades.
We have successfully computed an energetic map of the pericyclic reaction cascade above that leads to endiandric acids B, C, F, and G and have made substantial progress towards the synthesis of polyenes for use in this and related cascades. A highlight is the rapid synthesis of the enyne building blocks below from a common precursor.