Enantiomers of 2,2'-Spirobichromenes: Energy Barrier for Thermal Racemization during HPLC on Tribenzoylcellulose

Abstract

As a first case in the field of spirochromenes, the energy barrier for thermally reversible ring opening of 2,2'-spirobichromenes (Scheme) is measured by racemization of preparatively enriched enantiomers. In addition, this barrier is estimated via racemization during HPLC (Fig.) on tribenzoylcellulose without preparative enrichment. The significance of the latter procedure is discussed.