- Synthesis of labile all-trans-7,8,7′,8′-bis-acetylenic carotenoids by bi-directional Horner-Wadsworth-Emmons condensation
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A new stereoselective synthesis of the C40-bis-acetylenic carotenoids all-trans-(3R,3′R)-alloxanthin and all-trans-3,4,7,8,3′,4′,7′,8′-octadehydro-β,β-carotene, both compounds featuring a stereochemically labile C7-C10 enyne, based on a bi-directional Horner-Wadsworth-Emmons (HWE) reaction of a C15-phosphonate and a central C10-dialdehyde, is reported. The triene unit of the latter fragment was synthesized using the acyclic metathesis/dimerization reaction.
- Vaz, Belén,Fontán, Noelia,Casti?eira, Marta,álvarez, Rosana,De Lera, ángel R.
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supporting information
p. 3024 - 3031
(2015/03/18)
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- Synthesis of (3S,3′S)- and meso-stereoisomers of alloxanthin and determination of absolute configuration of alloxanthin isolated from aquatic animals
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In order to determine the absolute configuration of naturally occurring alloxanthin, a HPLC analytical method for three stereoisomers 1a-c was established by using a chiral column. Two authentic samples, (3S,3?S)- and meso-stereoisomers 1b and 1c, were ch
- Yamano, Yumiko,Maoka, Takashi,Wada, Akimori
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p. 2623 - 2632
(2014/06/10)
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- Stereoselective total synthesis of the acetylenic carotenoids alloxanthin and triophaxanthin
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Stereoselective total synthesis of the C40-diacetylenic carotenoid alloxanthin (1) and the C31-acetylenic apocarotenoid triophaxanthin (2) was accomplished by Wittig condensation of C 10-dialdehyde 20 or C16-ket
- Yamano, Yumiko,Chary, Mahankhali Venu,Wada, Akimori
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experimental part
p. 4103 - 4108
(2012/06/15)
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- Total synthesis of naturally configured pyrrhoxanthin, a carotenoid butenolide from plankton
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A carotenoid from the chemical kitchen: Two sequential Stille couplings of an unsymmetric distannane building block with a bromoolefin and a bromoalkyne terminated a highly convergent synthesis of the title compound, pyrrhoxanthin (see scheme).
- Burghart, Johen,Brueckner, Reinhard
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scheme or table
p. 7664 - 7668
(2009/04/11)
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- Stereocontrolled synthesis of optically active β-D-glucopyranosides of 3-hydroxy-7,8-didehydro-β-ionol
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A stereocontrolled synthesis of optically active β-D-glucopyranosides 1-4 of 3-hydroxy-7,8-didehydro-β-ionol utilizing an asymmetric transfer hydrogenation to α,β-acetylenic ketones catalyzed by chiral ruthenium complexes as the key step is described.
- Yamano, Yumiko,Watanabe, Yasuko,Watanabe, Naoharu,Ito, Masayoshi
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p. 2017 - 2018
(2007/10/03)
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- Ethynylcyclohexene compounds
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A process for the manufacture of compounds of the general formula STR1 wherein R1 signifies hydroxy or an etherified hydroxy group, and of zeaxanthin by converting a compound of the general formula STR2 wherein R1 has the above signi
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- 88. Technical Procedures for the Syntheses of Carotenoids and Related Compounds from 6-Oxo-isophorone: Syntheses of (3R,3'R)-Zeaxanthin
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Starting from the readily available, optically active (4R)-hydroxy-2,2,6-trimethylcyclohexanone (2), a new technical synthesis of (3R,3'R)-zeaxanthin is described.According to a completely new C9 + C2 + C4= C15 scheme, the ketone 2 was protected, ethynyla
- Soukup, Milan,Widmer, Erich,Lukac, Theodor
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p. 868 - 873
(2007/10/02)
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