Synthetic Studies in the Polyene Series. II.Synthesis of 15,15\u27 -Dihydro-B -carotene

The compound mentioned in the title has been prepared by condensation of 3,8-dimethyl-3,8-dihydroxy-decadiyne-(1,9) with two moles of 4-[2\u27,6\u27,6\u27 -trimethyl-cyclohexene-(l \u27) - y l]-2-methy lbuten-( 3)-al-(l), followed by dehydration and partial hydrogenation of acetylenic bonds. Intermedia tes and the fina l product were purified by absorption chromatography, and their structures were proved by spectroscopic and analytical methods