cas 514-78-3, Canthaxanthin | Articles data

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Cantharidin preparation method
The invention belongs to the field of compound synthesis, and relates to a cantharidin preparation method, which comprises: carrying out an oxidation reaction on beta carotene in a solvent in the presence of an oxidizing agent, a catalyst and a strong acid salt of divalent manganese ions, performing standing for layering after the oxidation reaction is finished, washing and purifying the oil layer, and concentrating to remove the solvent, and then adding an isomerization solvent to carry out isomerization reaction, and filtering and drying after the isomerization reaction is finished to obtainthe all-trans cantharidin. The cantharidin prepared by adopting the method provided by the invention has the advantages of good oxidation effect, lower oxidant dosage and higher cantharidin yield (upto 86% or above), and the obtained cantharidin is a purple red acicular crystal with the content of more than 90%. Then, a water layer is treated by adopting the method provided by the invention andthen is recycled, so that the consumption of an oxidant can be reduced, the cost is reduced, and meanwhile, the discharge of halogen-free acid salt wastewater is realized.
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Paragraph 0043-0057; 0062-0063

(2021/03/30)

Practical synthesis of canthaxanthin
In this study, a novel route for the total synthesis of canthaxanthin is described. The synthesis is firstly based on an epoxidation of α-ionone with metachloroperbenzoic acid to afford the epoxide, followed by conversion of the epoxide to 3-hydroxyl-β-ionone in the presence of sodium methoxide. Next, 3-hydroxyl-C14-aldehyde was obtained by a Darzens condensation with 4-hydroxyl-β-ionone and methyl chloroacetate, which can be converted to 3-hydroxyl-C15-phophonate via a Wittig–Horner condensation with tetraethyl methylenebisphosphonate. Then, a Wittig–Horner condensation with 3-hydroxyl-C15-phosphonate and C10-trienedial resulted in 4,4′-dihydroxyl-β-carotene, followed by an oxidation afforded the target product canthaxanthin. The overall yield of this route is 37% from α-ionone. The synthetic steps are easily operated and are practical for the large-scale production.
Pi, Shiqing,Xi, Meiyang,Deng, Liping,Xu, Huiting,Feng, Chengjie,Shen, Runpu,Wu, Chunlei
p. 493 - 497
(2019/11/03)

Synthesis method of canthaxanthin
The invention discloses a method for preparing canthaxanthin by oxidizing beta-carotene. The method comprises the following steps: dissolving beta-carotene in an organic solvent, adding a catalyst andcerium dioxide, uniformly mixing, stirring, turning on an ultraviolet lamp for irradiation, dropwise adding a sulfuric acid aqueous solution under the irradiation condition of the ultraviolet lamp, reacting to generate a crude product containing canthaxanthin, filtering, washing with water, taking an organic phase, removing the solvent, recrystallizing, filtering and drying to obtain a canthaxanthin product. The method is mild and simple in reaction condition and high in yield.
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Paragraph 0043-0058

(2020/07/28)

Method for preparing canthaxanthin by oxidizing beta-carotene
The invention provides a method for preparing canthaxanthin by oxidizing beta-carotene. The method comprises the following steps of: dissolving beta-carotene in a solvent, and carrying out oxidation reaction in the presence of a catalyst and an oxidant to prepare canthaxanthin; wherein the catalyst is a metal calcium salt compound. The cheap metal calcium salt compound is used as the catalyst, anda peroxide is used as the oxidant to catalyze the oxidation reaction, so that the method has the advantages of mild process route conditions, environment friendliness, simple and convenient operationand easy industrial production.
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Paragraph 0026-0047

(2020/11/05)

Method for preparing cyclic alpha, beta-unsaturated ketone
The invention provides a method for preparing cyclic alpha, beta-unsaturated ketone. According to the method, a compound shown in the formula (I) is oxidized by oxygen through electrochemical synthesis in the presence of a catalyst and an auxiliary agent to prepare a compound shown in the formula (II). The method is mild in condition, high in atom economy and less in three wastes, and the productyield is higher than 95%.
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Paragraph 0056-0057

(2020/07/13)

Process method for synthesizing canthaxanthin
The invention relates to a process method for synthesizing canthaxanthin. The process method comprises the following steps: 1, oxidizing a compound (2) to obtain a compound (3); and 2, carrying out acondensation reaction on the compound (3) and decadialdehyde to obtain the final product canthaxanthin (1). The invention provides another process route for synthesizing canthaxanthin. The route is simple, only two steps are needed, the canthaxanthin is gradually separated out from a liquid reaction system in the reaction process, the purity is very high, further purification measures are not needed, the yield is not lower than that of an existing canthaxanthin preparation process, the purity is higher than that of the existing process, the cost is lower, and industrial popularization is easy.
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Paragraph 0015; 0046-0056; 0060-0062

(2020/07/24)

Method for preparing canthaxanthin from beta-carotene by oxidization
The invention discloses a method for preparing canthaxanthin from beta-carotene by oxidization. The canthaxanthin is prepared from beta-carotene by one-step oxidization in the presence of a catalyst and oxidizing agents including sodium nitrate and carbon dioxide, and the method has the advantages of mild reaction conditions, environmental friendliness, high yield and the like.
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Paragraph 0065-0086

(2019/09/17)

Method for preparing canthaxanthin
The invention belongs to the field of organic synthesis, and specifically discloses a method for preparing canthaxanthin. The method comprises the following steps: dissolving beta-carotene, an oxidantI and a phase transfer catalyst in an organic solvent; adding an oxidant II at 0-15 DEG C; performing oxidation reaction at 0-15 DEG C after the addition is completed; and then, separating an oil phase from the obtained oxidation reaction product and performing isomerization reaction to obtain all-trans canthaxanthin, wherein the oxidant I is a peroxide oxidant, and the oxidant II is a hypochlorite oxidant. The method for preparing canthaxanthin provided by the invention can be adopted to significantly increase the yield of reaction, reduce the dosage of the oxidants and shorten the reactiontime.
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Paragraph 0045-0046; 0047-0048; 0049-0050; 0051-0070

(2019/03/08)

Method for preparing canthaxanthin by beta-carotene
The invention discloses a novel synthesis method for preparing canthaxanthin by beta-carotene one-step oxidization. According to the method, beta-carotene serves as an initial raw material, a cyclodextrin compound serves as a phase transfer catalyst, molecular oxygen serves as an oxidizing agent under catalysis of a copper compound and amino acid, and the canthaxanthin is prepared by one-step oxidization. The route is high in reaction selectivity and simple in process and facilitates industrial production.
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Paragraph 0037-0038; 0039-0040; 0041-0042; 0043-0058

(2019/03/08)

Method for oxidizing beta-carotene to prepare canthaxanthin
The invention discloses a method for oxidizing beta-carotene to prepare canthaxanthin. The beta-carotene reacts with an oxidant copper salt solution in the presence of a catalyst and an auxiliary agent to prepare the canthaxanthin; the problems in the prior art that the yield of a product is low and the environment is polluted are mainly solved.
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Page/Page column 6; 7

(2018/07/30)

A oxidation-β - carotene preparation canthaxanthins method (by machine translation)
The invention discloses a oxidation β - carotene preparation canthaxanthins method, characterized in that β - carotene in the catalyst and the assistant, hydrogen peroxide oxidation reaction with the oxidizing agent preparation canthaxanthins. To solve the problems in the prior art in the product yield is low, the problem of environmental pollution. (by machine translation)
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Paragraph 0052-0067

(2019/01/07)

Method for preparing canthaxanthin through oxidation of beta-carotene
The invention discloses a method for preparing canthaxanthin through oxidation of beta-carotene. The method comprises the steps as follows: beta-carotene is dissolved in an organic solvent and oxidized to canthaxanthin with an oxidizing agent capable of producing oxygen atoms under the action of an allyl oxidation catalyst shown in a compound I and a cocatalyst capable of producing iodine anions.The method has the benefits as follows: halate waste difficult to treat is not produced and the method has the advantages of being green, environmentally friendly and high in yield.
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Paragraph 0051-0053; 0054-0057; 0058; 0059; 0060

(2018/06/26)

Method for preparing canthaxanthin through oxidation
The invention discloses a method for preparing canthaxanthin through oxidation.The method includes the steps that beta-carotene serves as the raw material, sulfur oxide urea or urea peroxide serves as an oxidizing agent, an oxidizing reaction is conducted, and the canthaxanthin is obtained.The method has the advantages that operation is simple, the reaction is stable, and the trigger condition is mild; the oxidizing agents including sulfur oxide urea and urea peroxide can be decomposed into H2O2 and elemental oxygen in solvent, O2 is released slowly, the content of active oxygen is high, stability is high, the utility of time is long, no side effect exists, no toxin or public hazard exists, and it is beneficial to achieve industrialized clean production.
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Paragraph 0030; 0031

(2016/12/01)

Catalytic properties and reaction mechanism of the CrtO carotenoid ketolase from the cyanobacterium Synechocystis sp. PCC 6803
CrtW and CrtO are two distinct non-homologous β-carotene ketolases catalyzing the formation of echinenone and canthaxanthin. CrtO belongs to the CrtI family which comprises carotene desaturases and carotenoid oxidases. The CrtO protein from Synechocystis sp. PCC 6803 has been heterologously expressed, extracted and purified. Substrate specificity has been determined in vitro. The enzyme from Synechocystis is basically a mono ketolase. Nevertheless, small amounts of diketo canthaxanthin can be formed. The poor diketolation reaction could be explained by the low relative turnover numbers for the mono keto echinenone. Also other carotenoids with an unsubstituted β-ionone ring were utilized with low conversion rates by CrtO regardless of the substitutions at the other end of the molecule. The CrtO ketolase was independent of oxygen and utilized an oxidized quinone as co-factor. In common to CrtI-type desaturases, the first catalytic step involved hydride transfer to the quinone. The stabilization reaction of the resulting carbo cation was a reaction with OH - forming a hydroxy group. Finally, the keto group resulted from two subsequent hydroxylations at the same C-atom and water elimination. This reaction mechanism was confirmed by in vitro conversion of the postulated hydroxy intermediates and by their enrichment and identification as trace intermediates during ketolation.
Breitenbach, Juergen,Gerjets, Tanja,Sandmann, Gerhard
p. 86 - 91
(2013/03/28)

METHOD FOR THE PREPARATION OF OXYCAROTENOIDS
A high-yield process for preparing astaxanthin (3,3'-dihydroxy-β, β- carotene-4, 4'- dione) from silylated derivatives of zeaxanthin (3,3'-dihydroxy-β, β- carotene-3, 3'-diol), whether it be of synthetic or natural origin, is described.
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Page/Page column 10-11

(2010/07/10)

Fast regeneration of carotenoids from radical cations by isoflavonoid dianions: Importance of the carotenoid keto group for electron transfer
Electron transfer to radical cations of β-carotene, zeaxanthin, canthaxanthin, and astaxanthin from each of the three acid/base forms of the diphenolic isoflavonoid daidzein and its C-glycoside puerarin, as studied by laser flash photolysis in homogeneous methanol/chloroform (1/9) solution, was found to depend on carotenoid structures and more significantly on the deprotonation degree of the isoflavonoids. None of the carotenoid radical cations reacted with the neutral forms of the isoflavonoids while the monoanionic and dianionic forms of the isoflavonoids regenerated the oxidized carotenoid. Electron transfer to the β-carotene radical cation from the puerarin dianion followed second order kinetics with the rate constant at 25 °C k2 = 5.5 × 109 M-1 s-1, zeaxanthin 8.5 × 109 M-1 s-1, canthaxanthin 6.5 × 1010 M-1 s-1, and astaxanthin 11.1 × 1010 M-1 s-1 approaching the diffusion limit and establishing a linear free energy relationship between rate constants and driving force. Comparable results found for the daidzein dianion indicate that the steric hindrance from the glucoside is not important suggesting the more reducing but less acidic 4′-OH/4′-O- as electron donors. On the basis of the rate constants obtained from kinetic analyses, the keto group of carotenoids is concluded to facilitate electron transfer. The driving force was estimated from oxidation potentials, as determined by cyclic-voltametry for puerarin and daidzein in aqueous solutions at varying pH conditions, which led to the standard reduction potentials E° = 1.13 and 1.10 V versus NHE corresponding to the uncharged puerarin and daidzein. For pH > pka2, the apparent potentials of both puerarin and daidzein became constants and were E° = 0.69 and 0.65 V, respectively. Electron transfer from isoflavonoids to the carotenoid radical cation, as formed during oxidative stress, is faster for astaxanthin than for the other carotenoids, which may relate to astaxanthins more effective antioxidative properties and in agreement with the highest electron accepting index of astaxanthin.
Han, Rui-Min,Chen, Chang-Hui,Tian, Yu-Xi,Zhang, Jian-Ping,Skibsted, Leif H.
scheme or table
p. 126 - 132
(2010/05/11)

Nucleophilic reactions of charge delocalised carotenoid mono- and dications
In the present study insight was gained on the larger complexity of cationic mixtures of diaryl (φ,φcarotene, isorenieratene) and aliphatic (Φ,Φ-carotene, lycopene) carotenes, prepared by reaction with BF 3-etherate, compared with β,β-carotene. Chemical reactions of the mono- and dications prepared in situ from the allylic carotenols β,β-caroten-4-ol (isocryptoxanthin) and β,β-carotene-4,4'- diol (isozeaxanthin), and from isorenieratene and lycopene were investigated using selected O, N and S nucleophiles; water, methanol, azide and thioacetate. In total 22, including 18 new, neutral carotenoid products were isolated and identified by VIS, MS and NMR (in part) spectroscopy. Their structures were compatible with the structures of the cationic intermediates. The formal addition of hydride to the various dications, required to rationalise minor reaction products, is discussed in terms of more likely hydrogen radical or proton transfer in cationic reactions. Extensive E/Z isomerisation was observed for all quenching products. The potential use of carotenoid cations for the synthesis of 4,(4')-substituted β,β-carotenes and 7-oxabicycloheptane derivatives is discussed.
Kildahl-Andersen, Geir,Bruas, Liv,Lutnaes, Bjart Frode,Liaaen-Jensen, Synnove
p. 2496 - 2506
(2007/10/03)

Process for the production of canthaxanthin
The invention relates to a process for the production of canthaxanthin by oxidation of beta-carotene or carotinoids derived therefrom having conjugated double bonds.
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Page 4

(2008/06/13)

Preparation of 4,4′-diketo-β-carotene derivatives
A method of preparing β-carotene derivatives such as canthaxanthin and astaxanthin is described. The method employs an in situ system to generate hypobromous acid as the oxidizing agent using a salt of sulfite, hydrogen sulfite or bisulfite in combination with a bromate salt. Astaxanthin and canthaxanthin are obtained in good yield with a significantly reduced reaction time.
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Page column 4

(2008/06/13)

Process for the preparation of an xanthophyll
The present invention relates to a process for the preparation of an xanthophyll, and in particular to a process for the preparation of an xanthophyll through the oxidation of a carotenoid in the presence of hydrogen peroxide and an iodine-containing compound. In particular, the process of the invention applies to the oxidation of β-carotene to produce canthaxanthin, and to the oxidation of lutein or zeaxanthin to produce astaxanthin.
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(2008/06/13)

Process for making 4,4′-diketo-carotenoids
A process for the manufacture of a symmetrical, terminally ring-substituted polyenes by reacting a polyene di(O,O-dialkyl acetal) with a cyclic dienol ether in the presence of a Lewis or Br?nsted acid, hydrolyzing the condensation product resulting therefrom and cleaving off alcohol under basic or acidic conditions from the polyene derivative produced at this stage. The novel cyclic dienol ethers, as well as, novel intermediates resulting from the condensation and additional intermediates in this process form further aspects of the invention. The final products are primarily carotenoids, which find corresponding use, e.g., as colorings and pigments for foodstuffs, animal products, etc.
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(2008/06/13)

Reactivity of polyenes in solid-state autoxidation
The reactivity of polyenes (β-carotene, canthaxanthin, lycopene and some retinyl polyenes as related compounds) in the solid state towards molecular oxygen at various temperatures and oxygen pressures was studied. The specimens were thin (ca 0.1 μm) amorphous films prepared by evaporation of one or two drops of appropriate solution on quickly rotating supports. The autoxidation was monitored by recording the changes in the electronic and infrared spectra of oxidizing films and was demonstrated to be a chain free-radical process with extremely high chain-initiation rates (10-5-10-6 mol 1-1 s-1). For various polyenes the kinetic parameters of the initiation reaction were measured. In the films of several polyenes (retinyl acetate, retinal, methyl retinoate, β-carotene), the formation of free radicals proceeds in the absence of oxygen and the mechanism of the process was suggested. The observed ratios of the propagation and termination rate constante depend on the oxygen pressure, indicating the involvement of polyenyl radicals in the chain termination process. The observed trends are explained using the concepts of the stabilization energy of radicals, the reversibility of oxygen addition to polyenyls and morphological features of polyene films. Copyright
Finkelshtein,Krasnokutskaya,Vakulova
p. 370 - 376
(2007/10/03)

C-15 phosphonate reagent compositions for the manufacture of compounds such as canthaxanthin and methods of synthesizing the same
The present invention describes novel C-15 allenic phosphonate reagent compositions of the formula: STR1 The invention also describes novel C-15 allylic phosphonate reagent compositions of the formula: STR2 The invention also describes methods of preparing canthaxanthin, the phosphonate reagent compositions, and a tertiary propargylic alcohol of the formula: STR3
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(2008/06/13)

Application of diphenyl diselenide as a new catalyst for photochemical stereoisomerization of carotenoids
In a comparative study, diphenyl diselenide was shown to be an alternative to iodine as a catalyst for photochemical E/Z isomerization of carotenoids. Suitable conditions for the stereomutation of zeaxanthin, violaxanthin, canlhaxanthin and fucoxanthin are reported. Photochemical allenic isomerization with increased R to S conversion was achieved by employing diphenyl diselenide rather than iodine as the catalyst. Reproducible and expedient artificial light conditions, avoiding insolation (sunlight), are reported. Diphenyl diselenide tolerated the presence of Huenig's base upon stereoisomerization of acid-sensitive carotenoids. Diphenyl ditelluride effected E/Z stereomutation, but no allenic R/S isomerization of fucoxanthin. The presence of base decreased the isomerization rate in the absence of catalyst and may serve to decrease undesirable E/Z stereoisomerization of base-stable carotenoids. Acta Chemica Scandinavica 1998.
Strand, Aase,Liaaen-Jensen, Synnove
p. 1263 - 1269
(2007/10/03)

Semiconductor photocatalysis: Photodegradation and trans-cis photoisomerization of carotenoids
In the presence of semiconductor CdS or ZnO particles, irradiation (>350 nm) of all-trans-β-carotene (II) in dichloromethane leads to rapid degradation of the carotenoid, which is relatively stable in the absence of the semiconductors. Canthaxanthin (I), however, undergoes significant photocatalyzed degradation only on ZnO, not on CdS. High-performance liquid chromatographic studies indicate that CdS catalyzes trans-cis photoisomerization of both I and II. As in the photoisomerization in the absence of semiconductor, the major cis isomers have the 9-cis and 13-cis configuration, but, under otherwise the same condition, the ratio of cis/trans isomers has doubled. In contrast to CdS, ZnO does not catalyze the photoisomerization of either I or II, although it enhances their rate of degradation. A photoisomerization mechanism involving carotenoid radicals formed by reaction with interstitial sulfur on the CdS surface is proposed.
Gao, Guoqiang,Deng, Yi,Kispert, Lowell D.
p. 3897 - 3901
(2007/10/03)

Relative one-electron reduction potentials of carotenoid radical cations and the interactions of carotenoids with the vitamin E radical cation
Pulse radiolysis studies have been used to determine the electron- transfer rate constants between various pairs of carotenoids, one of which is present as the radical cation. These dietary carotenoids include those of importance to vision, namely zeaxanthin and lutein. These results have suggested the order of relative ease of electron transfer between six carotenoids. Additional experiments, involving electron transfer between astaxanthin (ASTA), β-apo-8'-carotenal (APO), and vitamin E (TOH), lead to the following order in terms of relative ease of electron transfer for the seven carotenoid radical cations studied: astaxanthin > β-apo-8'-carotenal > canthaxanthin > lutein > zeaxanthin > β-carotene > lycopene, such that lycopene is the strongest reducing agent (the most easily oxidized) and astaxanthin is the weakest, and the radical cations of the visual carotenoids, lutein (LUT) and zeaxanthin (ZEA), are reduced by lycopene (LYC) but not by β-carotene (β-CAR). Work on 7,7'-dihydro-β-carotene (77DH) and vitamin E allows us to better understand the interaction of the vitamin E radicals with carotenoids.
Edge, Ruth,Land, Edward J.,McGarvey, David,Mulroy, Louise,Truscott, T. George
p. 4087 - 4090
(2007/10/03)

Selected cis/trans isomers of carotenoids formed by bulk electrolysis and iron(III) chloride oxidation
Bulk electrolysis and chemical oxidation with FeCl3 of all-trans canthaxanthin (I) and 8′-apo-β-caroten-8′-al (II) gave primarily the 9- and 13-cis-isomers, which were separated by HPLC and identified by 1H NMR spectroscopy. Optical absorption measurements showed that the 15-cis, 9,13-di-cis isomers of I are also formed by these methods. In the case of the unsymmetrical compound II, additional isomers were formed. The cis isomers account for about 40-60% of products formed. Formation of the isomers is believed to occur by rotation about certain bonds in the cation radicals or dications, which are formed in the oxidation processes. The neutral cis species are then formed by an electron exchange reaction of the cis-cation radicals with neutral all-trans carotenoids in solution. The electrochemical and iron(III) chloride oxidation induced isomerization are shown to be efficient and improved methods for forming selected carotenoid isomers.
Wei, Chih-Chang,Gao, Guoqiang,Kispert, Lowell D.
p. 783 - 786
(2007/10/03)

Carotenoids enhance vitamin E antioxidant efficiency
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Bohm,Edge,Land,McGarvey,Truscott
p. 621 - 622
(2007/10/03)

Production of fine particle dye or drug preparations
Process for the production of fine-particle, essentially amorphous dye or drug preparations by converting a relatively coarse-particle dispersion or a solution into a colloidal dispersion in water, where the colloidal dispersion is generated at a temperature above the melting point of the dye or drug by admixing appropriately hot water (where appropriate under pressure) or an aqueous protective colloid solution so that an emulsion of a melt in aqueous medium is produced and is immediately spray-dried or converted by cooling into a suspension.
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(2008/06/13)

Interactions between carotenoids and the CCl3O2? radical
The reactions of CCl3O2? (a model of alkyl peroxyl radicals which can be selectively generated in nanoseconds) with a range of carotenoids (β-carotene, septapreno-β-carotene, canthaxanthin, astaxanthin, zeaxanthin, and lutein) in the heterogeneous micellar environment, aqueous 2% Triton X-100, have been studied by pulse radiolysis. For all carotenoids investigated two reaction products, absorbing in the near-infrared region, are observed and assigned to the carotenoid radical cation and an addition radical. With the exception of astaxanthin, the carotenoid radical cation formation is biexponential and the slower component matches the first-order decay of the addition radical. In the case of astaxanthin, no radical cation is formed directly by reaction with CCl3O2?, it is formed exclusively from the decay of the addition radical. The results are discussed in terms of the antioxidant properties of carotenoid pigments.
Hill, Tessa J.,Land, Edward J.,McGarvey, David J.,Schalch, Wolfgang,Tinkler, Jane H.,Truscott, T. George
p. 8322 - 8326
(2007/10/03)

Preparation of canthaxanthin and astaxanthin
A process for preparing canthaxanthin (Ia) and astaxanthin (Ib) of the formula I STR1 where R is H (a) or OH (b), comprises reacting a tertiary alcohol of the formula II STR2 where R is H (a) or OH (b), with trifluoroacetic acid, reacting the resulting novel trifluoroacetate of the formula III STR3 with triphenylphosphine, and reacting the resulting novel triphenylphosphonium trifluoroacetate of the formula IV STR4 with 2,7-dimethyl-2,4,6-octatriene-1,8-dial under the conditions of a Wittig synthesis. The present invention also relates to the novel trifluoroacetates of the formula III and the corresponding triphenylphosphonium trifluoroacetates of the formula IV.
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(2008/06/13)

Canthaxanthin. A new total synthesis
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Rosenberger,McDougal,Bahr
p. 2130 - 2134
(2007/10/02)

Manufacture of canthaxanthin
Process for the manufacture of canthaxanthin by oxidizing β-carotene, retro-dehydro-carotene or echinenone with a salt of chloric or bromic acid in the presence of a catalyst and of an inert diluent or solvent.
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(2008/06/13)

1-(2,6,6-Trimethyl-3-hydroxy-1-cyclohexen-1-yl)-3-methyl-penta-1,4-diene[or 1-yn-4-EN]-3-ols
A total synthesis of canthaxanthin, a known food coloring agent from alpha or retro ionone.
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(2008/06/13)

Sulphones
Sulphones of the formula: STR1 in which R is a substituted or unsubstituted alkyl, alkylaryl, aralkyl, or aryl radical, A is a radical containing one or more isoprene units which is saturated, unsaturated, or of the conjugated or unconjugated polyene type, which is unsubstituted or substituted by one or more functional groups, halogen atoms or alkyl groups, and which may be cyclic when the number of isoprene units is at least 2, and Q is hydrogen or a cyclic or acyclic hydrocarbon radical which is saturated, unsaturated, or of the conjugated or unconjugated polyene type, and which is unsubstituted or substituted by one or more functional groups, halogen atoms or alkyl groups are useful intermediates in the production of terpene compounds such as β-carotene and canthaxanthine.
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(2008/06/13)

Hydroxy-acetylene-substituted cyclohexenone
A total synthesis of canthaxanthin or dinor-canthaxanthin, known food coloring agents, from pentols.
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(2008/06/13)