- Total synthesis of (3R,3′R,6′R)-lutein and its stereoisomers
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(Chemical Equation Presented) (3R,3′R,6′R)-Lutein (1) is a major dietary carotenoid that is abundant in most fruits and vegetables commonly consumed in the U.S. and that accumulates in the human plasma, major organs, and ocular tissues. Numerous epidemiol
- Khachik, Frederick,Chang, An-Ni
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experimental part
p. 3875 - 3885
(2009/10/14)
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- Process for Synthesis of (3R,3'R,6'R)-Lutein and its Stereoisomers
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(3R,3′R,6′R)-Lutein and (3R,3′R)-zeaxanthin are two dietary carotenoids that are present in most fruits and vegetables commonly consumed in the US. These carotenoids accumulate in the human plasma, major organs, and ocular tissues. In the past decade, numerous epidemiological and experimental studies have shown that lutein and zeaxanthin play an important role in the prevention of age-related macular degeneration (AMD) that is the leading cause of blindness in the U.S. and Western World. The invention provides a process for the synthesis of (3R,3′R,6′R)-lutein and its stereoisomers from commercially available (rac)-α-ionone by a C15+C10+C15 coupling strategy. In addition, the present invention also provides access to the precursors of optically active carotenoids with 3-hydroxy-ε-end group that are otherwise difficult to synthesize. The process developed for the synthesis of lutein and its stereoisomers is straightforward and has potential for commercialization.
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Page/Page column 6-7; 20
(2009/10/30)
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- 4,5-Didehydro-9-demethyl-9-halo-5,6-dihydroretinals and their 9-cyclopropyl and 9-isopropyl derivatives - Simple preparation of α-ionone derivatives and pure (all-E)-, (9Z)- and (11Z)-α-retinals
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α-Ionone and several of its chemically modified derivatives have been prepared in high yield in full isomeric purity by a Wadsworth-Emmons procedure using imino-phosphonate anion reagents. Starting from α-ionone, 5-(2′,6′,6′-trimethylcyclo-2′-hexen-1′-yl) -4-penten-2-yn-1-al could be prepared in a high yielding one-pot procedure. The corresponding (9-Cl-, 9-Br- and 9-I-α-ionylidene)acetaldehyde system could be obtained in one step in a quantitative mixture of (9Z) and (all-E) isomers by 1,4-nucleophilic addition reactions. The pure (all-E) and (9Z) isomers could be separated by simple column chromatography. The corresponding [(9Z)- and (all-E)-9-demethyl-9-fluoro-α-ionylidene]acetaldehydes could also be obtained in pure form by simple column chromatography. These α-ionylidene systems could be easily converted either into the (all-E)-4,5-didehydro-9- demethyl-9-halo-5,6-dihydroretinals or the corresponding (9Z) isomers in two steps. Similar mixtures of the corresponding (9Z,11Z)-and (9Z)-nitriles could be obtained by normal chemistry. The (9Z,11Z) isomer is the main component of this mixture, and could be obtained in pure form. Subsequent reduction with DIBAL-H and careful workup gave the pure (9Z,11Z)-9-halo-retinals. These (9Z,11Z) isomers show a similar extreme acid sensitivity to the corresponding 9-halo-β-retinals. α-Retinal and its 9-demethyl, 19,19-ethano and 19,19-dimethyl derivatives have been prepared in the (all-E), (9Z), and (11Z) isomeric forms in a similar manner. The corresponding β-retinal and its 9-demethyl derivative in the various isomeric forms are known. In this paper the 19,19-ethano- and 19,19-dimethyl-β-retinals in the (all-E), (9Z), and (11Z) isomeric forms are also reported. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Wang, Yajie,Lugtenburg, Johan
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p. 3497 - 3510
(2007/10/03)
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