62285-98-7Relevant articles and documents
Preparation method of vitamin A acetate intermediate C15 and vitamin A acetate
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, (2020/08/18)
The invention provides a preparation method of a vitamin A acetate intermediate C15 and vitamin A acetate. The method comprises the following steps: taking 1-halogenated-2-methyl-4-acetoxy-2-butene asa raw material, preparing a corresponding Wittig reagent through a substitution reaction with triphenylphosphine or triester phosphite, then carrying out a Wittig reaction with beta-cyclocitral, hydrolyzing an ester group under an alkaline condition, acidifying to obtain a corresponding halide, and carrying out a substitution reaction with triphenylphosphine or triester phosphite again to prepareC15. The vitamin A acetate can be prepared by carrying out a Wittig reaction on the obtained C15 and 2-methyl-4-acetoxy-2-butenal under an alkaline condition. The method has the advantages of singlereaction type, easy operation and realization of reaction conditions, safe and environment-friendly operation, simple post-treatment and low cost; and the reaction activity is strong, the reaction selectivity is high, the atom economy is high, and the target product yield and purity are high.
Preparation method of vitamin A ester intermediate C15 and vitamin A ester
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, (2020/08/18)
The invention provides a preparation method of a vitamin A ester intermediate C15 and vitamin A ester. The method comprises the following steps: carrying out a halogenation reaction and a cyclizationreaction on 3, 7-dimethyl-3-hydroxy-1, 6-octadiene as an initial raw material, carrying out a substitution reaction on the obtained product and triphenylphosphine or triester phosphite to prepare a corresponding Wittig reagent, carrying out a Wittig reaction on the Wittig reagent and 2-methyl-4-acetoxy-2-butenal, performing acidifying, hydrolyzing and acidifying the obtained product, and carryingout a substitution reaction on the hydrolyzed and acidified product and triphenylphosphine or triester phosphite to prepare C15. The vitamin A ester can be prepared by carrying out a Wittig reaction on the obtained C15 and 2-methyl-4-R3 substituent carbonyloxy-2-butenal. The method has the advantages of single reaction type, easy operation and realization of reaction conditions, safe and environment-friendly operation, simple post-treatment and low cost; and the reaction activity is strong, the reaction selectivity is high, the atom economy is high, and the target product yield and purity arehigh.
All-Trans-Retinol: All-Trans-13,14-Dihydroretinol Saturase and Methods of Its Use
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Page/Page column 2; 19; 22; Sheet 22/24, (2008/12/08)
Compositions of all-trans-retinol: all-trans-13,14-dihydroretinal saturase and methods of use thereof are provided.
Longer polyenyl cations in relation to soliton theory
Kildahl-Andersen, Geir,Anthonsen, Thorleif,Liaaen-Jensen, Synnove
, p. 2803 - 2811 (2008/03/12)
The carotene-like polyenes decapreno-β-carotene (C50), C54-β-carotene (C54, first synthesis) and dodecapreno-β-carotene (C60) with 15, 17 and 19 conjugated double bonds, respectively, were synthesized by double Wittig reactions. Introduction of a leaving group in allylic position failed, and cations were obtained by hydride elimination effected by i) triphenylcarbenium tetrafluoroborate-d15, prepared by a new method, or ii) treatment with trifluoroacetic acid-d. Deuterated reagents were employed for product analysis by 1H NMR. Parallel experiments were performed with β,β-carotene (C40). NIR spectra at room temperature and at -15 °C were employed for characterisation and stability studies of the cationic products. In CH2Cl2 λmax in the 900-1350 nm region was recorded. NMR data for the cationic product of β,β-carotene obtained by the two new preparation methods were consistent with the two monocations previously characterised. The cationic products of the longer polyenes provided downfield-shifted, broadened signals, compatible with C50-monocation, mixed C54-mono- and dication and C60-dication. Combined NIR and NMR data suggest that the extent of charge delocalisation is limited by the maximum soliton width for cations obtained from linear polyenes with more than ca. 20 sp 2-hybridized carbon atoms. The Royal Society of Chemistry.
Synthesis of iodinated analogues of all trans retinoic acid (ATRA) for SPECT imaging
Li, Haibing,Morin, Christophe
, p. 5673 - 5676 (2007/10/03)
Two derivatives of all trans retinoic acid in which one of the methyl groups has been replaced by iodine have been prepared.
Constraints of opsin structure on the ligand-binding site: Studies with ring-fused retinals
Hirano, Takahiro,Lim, In Taek,Kim, Don Moon,Zheng, Xiang-Guo,Yoshihara, Kazuo,Oyama, Yoshiaki,Imai, Hiroo,Shichida, Yoshinori,Ishiguro, Masaji
, p. 606 - 615 (2007/10/03)
Ring-fused retinal analogs were designed to examine the hulatwist mode of the photoisomerization of the 9-cis retinylidene chromophore. Two 9-cis retinal analogs, the C11-C13 five-membered ring-fused and the C12-C14 five-membered ring-fused retinal derivatives, formed the pigments with opsin. The C11-C13 ring-fused analog was isomerized to a relaxed all-trans chromophore (λmax > 400 nm) at even - 269°C and the Schiff base was kept protonated at 0°C. The C12-C14 ring-fused analog was converted photochemically to a bathorhodopsin-like chromophore (λmax = 583 nm) at -196°C, which was further converted to the deprotonated Schiff base at 0°C. The model-building study suggested that the analogs do not form pigments in the retinal-binding site of rhodopsin but form pigments with opsin structures, which have larger binding space generated by the movement of transmembrane helices. The molecular dynamics simulation of the isomerization of the analog chromophores provided a twisted C11-C12 double bond for the C12-C14 ring-fused analog and all relaxed double bonds with a highly twisted C10-C11 bond for the C11-C13 ring-fused analog. The structural model of the C11-C13 ring-fused analog chromophore showed a characteristic flip of the cyclohexenyl moiety toward transmembrane segments 3 and 4. The structural models suggested that hula twist is a primary process for the photoisomerization of the analog chromophores.
Total Synthesis of C31-Methyl Ketone Apocarotenoids: Sintaxanthin and (3R)-3-Hydroxysintaxanthin
Haugan, Jarle Andre
, p. 657 - 664 (2007/10/02)
The previously undescribed (all-E)-2,7,11-trimethyl-12-oxo-2,4,6,8,10-tridecapentenal has been synthesised in 26percent overall yield in six steps from the readily available 3-methyl-2-penten-4-yn-1-ol and 2,7-dimethyl-2,4,6-octatrienedial.This C16-keto aldehyde was used in the first total synthesis of fully characterised (all-E)-sintaxanthin and optically active (all-E)-(3R)-3-hydroxysintaxanthin.The C16-keto aldehyde is a versatile building block for any C31-methyl ketone apocarotenoid.
Retinoids and Related Compounds. Part 14. A Novel Synthesis of Conjugated 4-Alkylidenebutenolides and Their Spectral Characterization
Ito, Masayoshi,Katsuta, Yuko,Yamano, Yumiko,Tsukida, Kiyoshi
, p. 987 - 994 (2007/10/02)
A novel synthesis (the sulfone method) of carotenoidal alkylidenebutenolides is described together with spectral characterization of the latter.
Catalytic hydrogenation
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, (2008/06/13)
Compounds of the formula: STR1 wherein R 1 is a 2,6,6-trimethyl-1-cyclohexen-1-yl or 2,3,6-trimethylphenyl group, either of which may be unsubstituted or substituted by a hydroxy group or a protected hydroxy group, R 2 is aryl, and X - is an anionare manufactured by hydrogenating a compound of the formula: STR2 wherein R 1, R 2 and X are as above, in an organic solvent or aqueous-organic solvent in the presence of a nickel-, palladium-, platinum-, cobalt-, rhodium-, iridium-, or ruthenium-containing catalyst.The process is suitable as an intermediate step in carotenoid and retinoid syntheses.
