Synthesen in der Carotinoid-Reihe. 5. Mitteilung. Anwendungen der Reaktion von<i>Whiting</i>
作者:O. Isler、M. Montavon、R. Rüegg、P. Zeller
DOI:10.1002/hlca.19560390216
日期:——
Starting from various C40-diols, 7, 7′-dihydro-β-carotene, dehydro- retro-carotene (isocarotene) and three new carotenoids were synthesized by the reaction of Whiting. In addition a new synthesis of β-carotene from β-C18-ketone, acetylene and vitamin A-aldehyde is described.
Additions 1,3-dipolaires du diazo-2-propane sur le diacetylene et evolution photochimique des 3H-pyrazoles formes.
作者:M. Franck-Neumann、P. Geoffroy、J.J. Lohmann
DOI:10.1016/s0040-4039(00)81767-0
日期:1983.1
Diacetylene reacts with 2-diazopropane to give the acetylenic 3H-pyrazole I and the bis 3H-pyrazole II. By photolysis both azo-heterocycles lead to rearranged acetylenic compounds. The observed products are best explained by the intervention of unsaturated carbenes which do not cyclize into cyclopropenes.
Synthese von optisch aktiven, nat�rlichen Carotinoiden und strukturell verwandten Naturprodukten. II. Synthese von (3 S, 3?S)-Astaxanthin
作者:Frank Kienzle、Hans Mayer
DOI:10.1002/hlca.19780610732
日期:1978.11.1
Synthesis of optically active natural carotenoids and structurally related compounds. II. Synthesis of (3S, 3′S)-astaxanthin
光学活性天然类胡萝卜素和结构相关化合物的合成。二。(3 S,3 'S)-虾青素的合成
Intramolecular exchange interactions in non-aromatic bis-nitronyl-nitroxides
作者:Christophe Stroh、Raymond Ziessel、Gabriele Raudaschl-Sieber、Frank H. Köhler、Philippe Turek
DOI:10.1039/b414284e
日期:——
Two bis-nitronyl-nitroxides linked by unsaturated non-aromatic spacers have been synthesized and investigated: 3D-NIT2 and DTD-NIT2. The magnetic properties of these diradicals have been investigated in the crystalline state by SQUID magnetometry and in dilute solution by EPR spectroscopy. According to magnetic measurements in the crystalline state both compounds experience strong antiferromagnetic exchange interactions. The singlet–triplet splitting has been estimated as ΔEST
= 95 K for 3D-NIT2, and ΔEST
= 75 K for DTD-NIT2. Solid-state MAS NMR spectroscopy has been used to determine the spin densities at the 1H and 13C nuclei of DTD-NIT2, thereby establishing spin polarization as the origin of the magnetic properties. The synthesis of an analogous mono-nitronyl-nitroxide has been undertaken in order to investigate the large intermolecular magnetic interactions observed in the crystalline state for 3D-NIT2.
Carotenoids and related compounds. Part XV. The structure and synthesis of phytoene, phytofluene, ζ-carotene, and neurosporene
作者:J. B. Davis、L. M. Jackman、P. T. Siddons、B. C. L. Weedon
DOI:10.1039/j39660002154
日期:——
Structures have been established for the polyenes, phytoene, phytofluene, ζ-carotene and neurosporene by spectral studies and synthesis. The stereochemistry of these polyenes is discussed.