Kinetic resolution in a bridgehead lithiation mediated by a chiral bis-lithium amide: assignment of the absolute configuration of clusianone.

A chiral base kinetic resolution of an advanced bicyclic intermediate enabled access to the polyprenylated phloroglucinol natural product (+)-clusianone in enantiomerically pure form. X-ray structure determination of another product obtained by the same method then allowed the absolute stereochemistry of (+)-clusianone to be assigned.