- Total synthesis of capsanthin and capsorubin using Lewis acid-promoted regio- and stereoselective rearrangement of tetrasubsutituted epoxides
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The synthesis of capsanthin 1 and capsorubin 2 was accomplished via the C15-cyclopentyl ketone 6 prepared by Lewis acid-promoted regio- and stereoselective rearrangement of the epoxy dienal 5. The Royal Society of Chemistry.
- Yamano, Yumiko,Ito, Masayoshi
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p. 3207 - 3212
(2008/03/14)
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- Kinetic Studies on the Thermal (Z/E)-Isomerization of C40-Carotenoids
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Rates of thermal (Z/E)-isomerization among all-E-, 9(9')Z-, 13Z-, 13'Z- and 15Z-isomers of zeaxanthin (1), natural violaxanthin (2), "semi-synthetic" violaxanthin (2a), capsorubin (3), capsanthin (4) and lutein epoxide (5) have been measured at temperatures over the range 333.4-368.4 K.From the specific rate constants calculated on the basis of four kinetic models, the Arrhenius and activation parameters have been derived.The effect of the different end groups and different solvents on the composition of the (Z/E)-equilibrium mixtures have been investigated as well.The rates of the isomerization reactions have been measured by HPLC, UV/VIS spectrophotometry and "classic" column chromatography.
- Molnar, Peter,Kortvelyesi, Tarnas,Matus, Zoltan,Szabolca, Jozsef
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p. 801 - 841
(2007/10/03)
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- Carotenoids and Related Compounds. Part 37. Stereochemistry and Synthesis of Capsorubin
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The two oxygen substitutents in the end groups of capsorubin were shown to be trans to one another by synthesis of optically inactive forms of the carotenoid, and of the isomers which have the corresponding cis-structure.The 3S,5R,3'S,5'R configuration thus established for the natural carotenoid was confirmed by synthesis of this stereoisomer from (+)-camphor.Cryptocapsin has the 3'S,5'R configuration, and the racemic form has been synthesised.Capsanthin has the 3R,3'S,5'R configuration.
- Bowden, Roy D.,Cooper, Robin D. G.,Harris, C. John,Moss, Gerard P.,Weedon, Basil C. L.,Jackman, Lloyd M.
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p. 1465 - 1474
(2007/10/02)
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