24190-29-2Relevant academic research and scientific papers
Photocaged Hydrocarbons, Aldehydes, Ketones, Enones, and Carboxylic Acids and Esters that Release by the Norrish II Cleavage Protocol and Beyond: Controlled Photoinduced Fragrance Release
Griesbeck, Axel G.,Porschen, Bj?rn,Kropf, Christian,Landes, Agnieszka,Hinze, Olga,Huchel, Ursula,Gerke, Thomas
, p. 539 - 553 (2017/01/25)
Five families of caged fragrance compounds that allow the storage and release of the following small volatile organic molecules are described: terpene hydrocarbons, aldehydes, ketones, Michael-type α,β-unsaturated enones, and carboxylic acids and esters. These caged molecules are released by photoexcitation via carbonyl-directed hydrogen-transfer processes and subsequent C-C bond cleavage (Norrish Type II) or by didenitrogenation of diazirines.
Controlled release of encapsulated bioactive volatiles by rupture of the capsule wall through the light-induced generation of a gas
Paret, Nicolas,Trachsel, Alain,Berthier, Damien L.,Herrmann, Andreas
supporting information, p. 2275 - 2279 (2015/02/19)
The encapsulation of photolabile 2-oxoacetates in core-shell microcapsules allows the light-induced, controlled release of bioactive compounds. On irradiation with UVA light these compounds degrade to generate an overpressure of gas inside the capsules, which expands or breaks the capsule wall. Headspace measurements confirmed the light-induced formation of CO and CO2 and the successful release of the bioactive compound, while optical microscopy demonstrated the formation of gas bubbles, the cleavage of the capsule wall, and the leakage of the oil phase out of the capsule. The efficiency of the delivery system depends on the structure of the 2-oxoacetate, the quantity used with respect to the thickness of the capsule wall, and the intensity of the irradiating UVA light.
PRO-FRAGRANCE COMPOUNDS
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Page/Page column 22, (2014/12/09)
A compound of Formula (I) wherein R1 represents a C3 to C20 hydrocarbon group derived from a fragrant alcohol of formula R1OH or from a fragrant aryl aldehyde or ketone of Formula (II), wherein: R2 is, independently, hydrogen atom, hydroxyl group, acetoxy group, -O(C=O)CH(CH3), optionally substituted C1-C6 alkyl group or C1-C6 alkoxy group, wherein any two of R2 may form an optionally substituted 5 or 6 membered ring, and R1 represents a radical derived from a fragrant alcohol of formula R1OH or from a fragrant aldehyde or from a fragrant aryl aldehyde or ketone of formula (II). The compounds are useful for example as a precursor for the prolonged delivery or release of fragrant compounds such as fragrant alcohols or aldehydes.
ω-Sulfonic-perfluoroalkylated poly(styrene-maleic anhydride)/silica hybridized nanocomposite as a new kind of solid acid catalyst
Lin, Zhenghuan,Huang, Limei,Ling, Qidan,Chen, Hong,Zhao, Chengxue
, p. 73 - 79 (2013/01/14)
A new kind of ω-sulfonic-perfluoroalkylated poly(styrene-maleic anhydride)/silica hybrid nanocomposite FSMA/SiO2 has been synthesized under mild conditions by perfluoroalkylation of styrene-maleic anhydride copolymer (SMA) with ω-fluorosulfonylperfluorodiacyl peroxides (SFAP), and followed in turn by aminolysis using (3-aminopropyl)triethoxysilane (APTES), alkali hydrolysis, gelation with tetraethoxysilane (TEOS) and finally acidification. The hybrid solid acid FSMA/SiO2 with terminal perfluoroalkylsulfonic and carboxyl groups was characterized by FTIR, SEM, TEM, TGA, XPS, EDX, acidimetry and nitrogen sorption technique. Its pore structure, acid strength and acid amount were easily modulated by controlling the gelation and perfluoroalkylation conditions. The catalytic activity and selectivity, as well as reusability of FSMA/SiO2 were tested in three important reactions, namely, cyclization of pseudoionone, condensation of indole and esterification of benzoic acid. Owing to the higher exchange capacity than that of Nafion/SiO2, and the stronger acidity than that of Amberlyst-15, the nanocomposite FSMA/SiO2 showed higher activity and selectivity than these commercial solid acids in the reactions.
Method for producing optically active α-ionone
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Page/Page column 43, (2011/04/14)
Provided that a method for inexpensively producing optically active α-ionone with a high yield and a high asymmetric yield and with good workability in a short process, and a perfume composition comprising the optically active α-ionone obtained by the aforementioned method. A method for producing optically active α-ionone, comprising allowing α-ionone as a mixture of optical isomers to react with an esterification agent, and hydrolyzing the obtained α-ionone enol ester; a method for producing optically active α-ionone comprising subjecting α-ionone as a mixture of optical isomers to an asymmetric reduction, allowing the obtained optically active α-ionol to react with an esterification agent to give an optically active α-ionol ester, hydrolyzing the obtained optically active α-ionol ester after purification as necessary, and then oxidizing the obtained optically active α-ionol; and a perfume composition comprising thus obtained optically active α-ionone.
Cyclization of pseudoionone into α-Ionone over heteropolyacid supported on mesoporous silica SBA-15
Rachwalik,Michorczyk,Ogonowski
experimental part, p. 1384 - 1390 (2012/02/02)
Cyclization of pseudoionone into α-ionone was performed over the series heteropolyacid supported on SBA-15 in liquid-phase at 363 and 373 K using a batch reactor. It has been demonstrated that the liquid-phase synthesis of α-ionone by pseudoionone cyclization can be efficiently achieved on heteropolyacid/SBA-15 materials. The high catalytic performance of PW 12/SBA-15 materials is due to their strong Bronsted acidity, high dispersion of active phase and also to absence of steric constraints for pseudoionone cyclization. PW12/SBA-15 catalysts are specially active and selective for this reaction giving predominantly α-ionone, as the main product, with high yield (about 60% at 373 K after 2 h) close to that obtained via the homogeneous synthesis. This catalytic system is more active and efficient in comparison with heteropolyacid supported on commercial silica. In order to achieve comparable amount of α-ionone, as is got for PW 12/SBA-15, belongs to apply five times more of the catalyst based on classical SiO2.
Gold-mediated synthesis of α-ionone
Merlini, Valentina,Gaillard, Sylvain,Porta, Alessio,Zanoni, Giuseppe,Vidari, Giovanni,Nolan, Steven P.
scheme or table, p. 1124 - 1127 (2011/03/22)
A simple and convenient synthesis of α-ionone, an important component of flowers and fragrances, is reported. The key step in the formation of the α,β-unsaturated ketone moiety involves an NHC-AuI catalyzed Meyer-Schuster-like rearrangement of readily prepared propargylic esters. The complex [{Au(IPr)}2(μ-OH)][BF4] proved to be the most efficient catalyst leading to α-ionone in 70% yield from a propargylic benzoate. This optimized procedure represents a valuable and attractive alternative to classical methods leading to α,β- unsaturated ketones, such as the Wittig or aldol reactions.
Synthesis of ionones on solid Br?nsted acid catalysts: Effect of acid site strength on ionone isomer selectivity
Díez,Apesteguía,Di Cosimo
experimental part, p. 267 - 274 (2010/11/19)
The effect of Br?nsted acid site strength on the liquid-phase conversion of pseudoionone to ionone isomers (α-, β- and γ-ionone) was studied on resin Amberlyst 35W, silica-supported heteropolyacid (HPAS) and silica-supported triflic acid (TFAS). Catalyst acidity was probed by temperature-programmed desorption of NH3 coupled with infrared spectra of adsorbed pyridine. The initial pseudoionone conversion rate followed the order: TFAS > Amberlyst 35W ≈ HPAS. Synthesis of the three ionone isomers occurred via a common cyclic carbocation intermediate formed from the activation of the pseudoionone molecule on Br?nsted acid sites. Initial ionone mixtures containing a α:β:γ isomer distribution of about 40:20:40 were formed, irrespective of the acid site strength. But the ionone mixture composition changed with the progress of the reaction because γ-ionone was consecutively converted to α-ionone on HPAS and Amberlyst 35W, whereas the stronger acid sites of TFAS converted γ-ionone to β-ionone.
A simple and versatile re-catalyzed meyer-schuster rearrangement of propargylic alcohols to α,β-unsaturated carbonyl compounds
Stefanoni, Massimo,Luparia, Marco,Porta, Alessio,Zanoni, Giuseppe,Vidari, Giovanni
scheme or table, p. 3940 - 3944 (2009/12/03)
The development of a general catalytic procedure for the rapid and efficient 1,3-rearrangement of free secondary and tertiary propargylic alcohols to the corresponding α,β-unsaturated carbonyl compounds using available [ReOCl3(OPPh3)-(SMe2)] complex, was reported. The reaction was carried out under neutral environmental conditions with no racemization of potentially enolizable stereocenters with virtually complete E stereoselectivity. The reaction under dimethoxyethane, proceeded at the lower rate than in THF, but with reduced by-products and the yield obtained were highly significant. The reaction was reported to increase constantly at the expense of the (Z)-isomer 2b, where the double bong isomerization was attributed to a catalytic effect of the rhenium complex. The resulted new version of Meyer-Schuster rearrangement will find enormous application in organic synthesis to develop one-pot multistep reaction sequences.
Process for the preparation of ionones and vitamin A, vitamin A derivatives, carotenes and carotenoids
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Page/Page column 7-8, (2008/12/05)
The present invention relates to a process for the preparation of β-ionones and/or α-ionones of the formulae II and III by acid catalyzed ring-closing of ψ-ionones of the formula I wherein R1 to R7 are independently selected from hydrogen and C1-C4-alkyl, R8 is selected from hydrogen and C1-C4-alkyl and the hydroxyl group, R9 and R10 are independently selected from hydrogen and C1-C4-alkyl or R9 and R10 form together the oxygen of a carbonyl group, whereby if R9 and R10 form together the oxygen of a carbonyl group no α-isomer is formed comprising: a) reacting a ψ-ionone according to formula I in presence of a concentrated Br?nsted-acid having a pKs 3, and an organic solvent that is substantially immiscible with the concentrated acid and with an diluted aqueous solution of said acid; b) hydrolysis of the reaction product obtained in step a) by addition of water; and phase separation into an organic phase comprising the β-ionone and/or the α-ionone of the formulae II and III and into an aqueous diluted acid phase; wherein water is added in the hydrolysis step b) in an amount to achieve an acid concentration in said aqueous diluted acid phase of 45 to 65 wt-%, that also can be easily integrated in a process for the preparation of vitamin A, a vitamin A derivative, a carotene or a carotenoid.
