Synthesen in der Carotinoid-Reihe. 12. Mitteilung. Synthese von 11,11′-Di-cis-β-carotin nach einem neuen Aufbauprinzip
作者:O. Isler、L. H. Chopard-dit-Jean、M. Montavon、R. Rüegg、P. Zeller
DOI:10.1002/hlca.19570400517
日期:——
11,11′-Di·cis-β-carotene was synthesized awarding to a new scheme C14 + C12 + C14 = C40 by condensing the crystalline C12-di-acetylenic hydrocarbon 3,8-dimethyl-decatriene-(3,5,7)-diyne-(9) at both ends with β-C14-aldehyde followed by dehydration and partial hydrogenation of the triple bonds. 11,11′-Di-cis-β-carotene shows about one third of the vitamin A activity of all-trans-β-carotene and is structurally
通过缩合结晶的C 12-二炔烃3,8-二甲基-癸三烯-(11,11'-Di·顺式-β-胡萝卜素合成了一种新的方案C 14 + C 12 + C 14 = C 40 3,5,7)-diyne-(9)在与β-C两端14 -醛,接着脱水和三键的部分氢化。11,11'-顺式-β-胡萝卜素显示出全反式-β-胡萝卜素约占维生素A活性的三分之一,并且在结构上与重要的视觉色素新-b-视黄素相关。雷斯蒂涅。11,11'-顺式-β-胡萝卜素比15,15'-对热更稳定顺式-β-胡萝卜素。
Unique properties of the 11-cis and 11,11′-di-cis isomers of β-carotene as revealed by electronic absorption, resonance Raman and 1H and 13C NMR spectroscopy and by HPLC analysis of their thermal isomerization
of other isomers. (2) The frequencies of the CC stretching Raman lines of these isomers are the same as that of the all-trans isomer, and do not follow the general trend of high-frequency shifts found in other mono-cis and di-cis isomers. The Raman lines due to the out-of-plane C–H wagging and methyl rocking modes appear in the 11,11′-di-cis isomer. (3) The 1H chemical shifts of these isomers indicate