ISOPIMARIC ACID

Abstract
Evidence is presented for the epimeric character of the C-13 substituents in pimaric and isopimaric acids and for the nuclear double bond location in isopimaric acid. This work, coupled with recent synthetic work and rotatory dispersion evidence, permits assignment of the structure and stereochemistry IV to isopimaric acid. Hydroboration and selenium dioxide oxidation of the acid are described.