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Vicente Ferreira - One of the best experts on this subject based on the ideXlab platform.
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Gas chromatography-olfactometry and chemical quantitative study of the aroma of six premium quality spanish aged red wines.
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography-olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which-1-nonen-3-one (temptatively) and 2-acetylpyrazine-are reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compounds related to the metabolism (2-phenylethanol, ethyl esters of isoacids, 3-methylbutyl acetate) or oxidative degradation of amino acids [phenylacetaldehyde and 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon)]. The correlation between the olfactometric intensities and the quantitative data is, in general, satisfactory if olfactometric differences between the samples are high. However, GC-O fails in detecting quantitative differences in those cases in which the olfactive intensity is very high or if odors elute in areas in which the odor chromatogram is too complex.
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Gas Chromatography-Olfactometry and Chemical Quantitative Study of the Aroma of Six Premium Quality Spanish Aged Red Wines
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography−olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which1-nonen-3-one (temptatively) and 2-acetylpyrazineare reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compo...
Laura Culleré - One of the best experts on this subject based on the ideXlab platform.
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Gas chromatography-olfactometry and chemical quantitative study of the aroma of six premium quality spanish aged red wines.
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography-olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which-1-nonen-3-one (temptatively) and 2-acetylpyrazine-are reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compounds related to the metabolism (2-phenylethanol, ethyl esters of isoacids, 3-methylbutyl acetate) or oxidative degradation of amino acids [phenylacetaldehyde and 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon)]. The correlation between the olfactometric intensities and the quantitative data is, in general, satisfactory if olfactometric differences between the samples are high. However, GC-O fails in detecting quantitative differences in those cases in which the olfactive intensity is very high or if odors elute in areas in which the odor chromatogram is too complex.
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Gas Chromatography-Olfactometry and Chemical Quantitative Study of the Aroma of Six Premium Quality Spanish Aged Red Wines
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography−olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which1-nonen-3-one (temptatively) and 2-acetylpyrazineare reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compo...
Juan Cacho - One of the best experts on this subject based on the ideXlab platform.
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Gas chromatography-olfactometry and chemical quantitative study of the aroma of six premium quality spanish aged red wines.
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography-olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which-1-nonen-3-one (temptatively) and 2-acetylpyrazine-are reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compounds related to the metabolism (2-phenylethanol, ethyl esters of isoacids, 3-methylbutyl acetate) or oxidative degradation of amino acids [phenylacetaldehyde and 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon)]. The correlation between the olfactometric intensities and the quantitative data is, in general, satisfactory if olfactometric differences between the samples are high. However, GC-O fails in detecting quantitative differences in those cases in which the olfactive intensity is very high or if odors elute in areas in which the odor chromatogram is too complex.
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Gas Chromatography-Olfactometry and Chemical Quantitative Study of the Aroma of Six Premium Quality Spanish Aged Red Wines
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography−olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which1-nonen-3-one (temptatively) and 2-acetylpyrazineare reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compo...
Ana Escudero - One of the best experts on this subject based on the ideXlab platform.
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Gas chromatography-olfactometry and chemical quantitative study of the aroma of six premium quality spanish aged red wines.
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography-olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which-1-nonen-3-one (temptatively) and 2-acetylpyrazine-are reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compounds related to the metabolism (2-phenylethanol, ethyl esters of isoacids, 3-methylbutyl acetate) or oxidative degradation of amino acids [phenylacetaldehyde and 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon)]. The correlation between the olfactometric intensities and the quantitative data is, in general, satisfactory if olfactometric differences between the samples are high. However, GC-O fails in detecting quantitative differences in those cases in which the olfactive intensity is very high or if odors elute in areas in which the odor chromatogram is too complex.
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Gas Chromatography-Olfactometry and Chemical Quantitative Study of the Aroma of Six Premium Quality Spanish Aged Red Wines
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Laura Culleré, Ana Escudero, Juan Cacho, Vicente FerreiraAbstract:The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography−olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which1-nonen-3-one (temptatively) and 2-acetylpyrazineare reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compo...
Chun-chen Liao - One of the best experts on this subject based on the ideXlab platform.
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Diels–Alder Reactions of Masked o‐Benzoquinones with 1‐Vinylcyclohexenes: A Short and Efficient Entry to Highly Functionalized Decahydrophenanthrene Skeleton
European Journal of Organic Chemistry, 2014Co-Authors: Gary Jing Chuang, Chi-phi Wu, Chun-chen LiaoAbstract:Masked o-benzoquinones (MOBs), which were generated in situ from 2-Methoxyphenols, underwent Diels–Alder reactions with 1-vinylcyclohexenes to produce the corresponding cycloaddition products, that is, decahydrophenanthrenes along with bicyclo[2.2.2]octenones. In the former case, the MOBs serve as the dienophile, and in the later case, the 1-vinylcyclohexenes act as the dienophile. The obtained bicyclo[2.2.2]octenones could be transformed into the corresponding decahydrophenanthrenes through a Cope rearrangement at 220 °C. Thus, these tandem reactions provide a short and efficient entry to the decahydrophenanthrene skeleton from easily available 2-Methoxyphenols.
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Photochemistry of Tricyclo[5.2.2.02,6]undeca-4,10-dien-8-ones: An Efficient General Route to Substituted Linear Triquinanes from 2-Methoxyphenols. Total Synthesis of (±)-Δ9(12)-Capnellene
Chemistry: A European Journal, 2010Co-Authors: Yu-yu Chou, Yen-shih Tung, Chun-chen LiaoAbstract:An efficient and short entry to polyfunctionalized linear triquinanes from 2-Methoxyphenols is described by utilizing the following chemistry. The Diels–Alder reactions of masked o-benzoquinones, derived from 2-Methoxyphenols, with cyclopentadiene afford tricyclo[5.2.2.02,6]undeca-4,10-dien-8-ones. Photochemical oxa-di-π-methane (ODPM) rearrangements and 1,3-acyl shifts of the Diels–Alder adducts are investigated. The ODPM-rearranged products are further converted to linear triquinanes by using an O-stannyl ketyl fragmentation. Application of this efficient strategy to the total synthesis of (±)-Δ9(12)-capnellene was accomplished from 2-methoxy-4-methylphenol in nine steps with 20 % overall yield.
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Stereocontrolled Synthesis of Polyfunctionalized cis-Decalins from 2-Methoxyphenols: Total Syntheses of (±)-Eremopetasidione, (±)-3β-Angeloyloxyfuranoeremophilane, and (±)-3β-Methacryloyloxyfuranoeremophilane
Journal of Organic Chemistry, 2008Co-Authors: Chun-chen LiaoAbstract:A four-step stereocontrolled synthesis of polyfunctionalized cis-decalins is described, involving oxidation of 2-methoxyphenol, intermolecular Diels−Alder reaction, olefination, and Cope rearrangem...
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Masked o-benzoquinone strategy in organic synthesis : Short and efficient construction of cis-decalins and linear triquinanes from 2-Methoxyphenols
Pure and Applied Chemistry, 2005Co-Authors: Chun-chen LiaoAbstract:The inter- and intramolecular Diels-Alder reactions of masked o-benzoquinones generated in situ from the oxidation of easily accessible 2-Methoxyphenols with diacetoxy- iodobenzene or bis(trifluoroacetoxy)iodobenzene provided cycloadducts in excellent regio- and stereoselectivity and good yields. A general approach to the synthesis of highly substi- tuted cis-decalins and triquinanes with complete stereocontrol from the cycloadducts has been developed. The applicability of our methodology is demonstrated by the total syntheses of several natural products.
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Intramolecular Diels-Alder reactions of brominated masked o-benzoquinones. A detour method to synthesize highly functionalized oxatricyclic [m.3.1.0] ring systems from 2-Methoxyphenols.
Journal of Organic Chemistry, 2002Co-Authors: Yi-ling Shen, Chun-chen LiaoAbstract:Intramolecular Diels−Alder (IMDA) reactions of masked o-benzoquinones (MOBs) 5a−d to 7a−d and 17a−d to 19a−d generated in situ from 2-Methoxyphenols 2−4 and 14−16, respectively, in the presence of alkenols 1a−d, resulting in highly functionalized oxatricyclic [m.3.1.0] ring systems are described. The MOBs 5a−d to 7a−d underwent the IMDA reactions to furnish the adducts 8a−d, 10a−d, and 12a−d (direct method) in poor yields with the concomitant formation of considerable amounts of unexpected byproducts 9a−d, 11a−d, and 13a−d, respectively. To avoid the formation of byproducts and to improve the yields of the desired cycloadducts, a detour method comprising sequential bromination of 2-Methoxyphenols 2−4, tandem oxidative acetalization−Diels−Alder reaction, and debromination has been developed. The oxidation of bromophenols 14−16 in the presence of alkenols 1a−d produced the corresponding MOBs 17a−d to 19a−d, which underwent cycloaddition to afford the cycloadducts 20a−d to 22a−d, respectively, as sole produc...
