A Study of Some cis—trans Isomeric Dehydro-β-carotenes

Abstract

Dehydro-β-carotene samples obtained from β-carotene constitute mixtures of stereoisomers from which two main crystalline cis forms were isolated. The interconversion of members of this stereoisomeric set was studied by thermic, photochemical and catalytic methods. The mixtures thus obtained contain less of the all-trans compound than in the case of carotenes. One of the observed cis dehydro-β-carotenes showed a degraded spectrum. No distinct cis-peak phenomena were observed in this "retro” system