In connection with the photochemical studies of the polyenes in the vitamin A series,3 we were in need of a complete set of geometric isomers of such a pentaene. The compound 11,12-dehydro-15-demethyl-β-axerophtene (I) was chosen because it has only four isomers and a procedure to the all-trans isomer is in the literature.4 A modification of this procedure may lead to the other isomers. The preparation and spectroscopic properties of all four isomers of I including the two sterically crowded 7-cis isomers, are now described here.
ASJC Scopus subject areas
- Organic Chemistry