- Mammalian exocrine secretions: X. Constituents of preorbital secretion of grysbok, Raphicerus melanotis
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Using electron impact and chemical ionization mass spectrometry with methane and nitric oxide as reactant gases in conjunction with mass spectral analysis of the dimethyl disulfide derivatives of unsaturated constituents, 51 compounds have been identified in addition to the compounds previously found in the preorbital secretion of the grysbok Raphicerus melanotis. The compounds identified are saturated, monounsaturated, and diunsaturated alcohols and formates, saturated and monounsaturated aldehydes, saturated carboxylic acids, γ- and δ-lactones, alkyl methyl sulfides, and β-hydroxyalkyl acetates. All of these compounds have unbranched structures. The constituent previously incorrectly identified as (Z)-5-tetradecen-1-ol, was found to consist of the coeluting (Z)-7- and (Z)-8-tetradecenols.
- Burger,Tien,Roux,Mo
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- Sensory-directed identification of creaminess-enhancing volatiles and semivolatiles in full-fat cream
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Aimed at defining the chemical nature of creaminess-related flavor compounds in dairy products on a molecular level, a full-fat cream was analyzed for sensorially active volatiles and semivolatiles by means of activity-guided screening techniques. Application of the aroma extract dilution analysis on an aroma distillate prepared from pasteurized cream (30% fat) revealed δ-decalactone, (Z)-6-dodeceno-γ-lactone, γ-dodecalactone, δ-dodecalactone, and 3-methylindole with by far the highest flavor dilution (FD) factors among the 34 odor-active volatiles identified. Using a complementary approach involving silica column chromatography and fractionated high-vacuum distillation combined with sensory experiments enabled the additional identification of δ-tetradecalactone, δ-hexadecalactone, γ-tetradecalactone, γ-hexadecalactone, and δ-octadecalactone as semivolatile flavor components in the cream fat. Although a series of lactones is present in dairy cream, spiking of cream samples with individual lactones revealed that only the δ-tetradecalactone is able to enhance the typical retronasal creamy flavor of the product when added in amounts above its theshold level of 66 μmol/kg. Rather than contributing to the retronasal aroma of cream, first evidence was found that, particularly, γ- and δ-octadecalactones and γ- and δ-eicosalactones are able to influence the melting behavior of cream in the oral cavity.
- Schlutt, Birgit,Moran, Noelia,Schieberle, Peter,Hofmann, Thomas
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p. 9634 - 9645
(2008/03/17)
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- Syntheses of 5-hexadecanolide, 6-acetoxy-5-hexadecanolide and tanikolide
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Total syntheses of 5-hexadecanolide (1), 6-acetoxy-5-hexadecanolide (2) and tanikolide (3) are described. 1-Bromoundecane (4) and 5-benzyl-1-pentanal (5) were chosen as starting materials. Wittig olefination and Grignard addition 4 and 5 afforded the 16-carbon skeleton, which underwent a series of functional group transformations to give δ-lactone derivatives 1, 2 and 3.
- Chang, Meng-Yang,Lin, Chien-Lun,Chen, Shui-Tein
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p. 787 - 794
(2007/10/03)
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- Lipase-catalysed Baeyer-Villiger Reactions
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The Baeyer-Villiger Oxidation of some 2- and 3-substituted cyclopentanones and cyclohexanones using myristic acid and hydrogen peroxide is catalysed by Candida anatarctica lipase.
- Lemoult, Stephanie C.,Richardson, Paul F.,Roberts, Stanley M.
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- A new approach for synthesis of pheromones: δ-Hexadecanolide and 2-methylheptadecane
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Solvomercuration of tridecene (1) and reductive bond formation with methylvinylketone in the presence of sodiium borohydride gives the key intermediate 6-acetoxy-2-oxo-heptadecane (2) which is converted to the title compounds (4) and (6).
- Dasaradhii, L,Ramesh, Ch,Bhalerao, U T
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p. 417 - 418
(2007/10/02)
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- PREPARATION OF 6-HYDROXY-2H-PYRAN-3(6H)-ONE FROM 2-FURYLCARBINOL BY PHOTOOXIDATION. SYNTHESIS OF A PHEROMONE OF VESPA ORIENTALIS
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Photooxidation of 2-furylcarbinols followed by reduction with triphenylphosphine afforded 6-hydroxy-2H-pyran-3(6H)-ones in excellent yield.The method was applied to synthesis of 6-undecyltetrahydro-2-pyrone, a pheromone of Vespa orientalis.
- Kuo, Yueh-Hsiung,Shih, Kae-Shyang
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p. 1941 - 1949
(2007/10/02)
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- A Direct Synthesis of γ-, δ-, and ε-Lactones Utilizing SmI2-induced Barbier-type Reaction in the Presence of Hexamethylphosphoric Triamide (HMPA)
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By using an efficient reduction system of SmI2-THF-HMPA, the coupling reaction of β-, γ-, or δ-bromoesters with carbonyl compounds was completed within a minute at room temperature affording γ-, δ-, or ε-lactones, respectively, in good yields.Cp2ZrCl2 was also found to be effective for the coupling with ketones.
- Otsubo, Kenji,Kawamura, Kisa,Inanaga, Junji,Yamaguchi, Masaru
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p. 1487 - 1490
(2007/10/02)
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- A NEW SYNTHESIS OF α,β-UNSATURATED γ- AND δ-LACTONS VIA INTRAMOLECULAR ACYLATION OF α-SULFINYL CARBANION
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A new synthesis of α,β-unsaturated γ- and δ-lactones involving the intramolecular acylation of α-sulfinyl carbanion followed by pyrolisis is described.
- Pohmakotr, Manat,Jarupan, Prapanpong
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p. 2253 - 2256
(2007/10/02)
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- Synthesis of γ- and δ-Lactones via Radical CC-Bond Formation Reaction
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Lactones 5 and 6 can be synthesized via solvomercuration of alkenes 1 and reductive CC-bond formation with acrylonitrile.
- Giese, Bernd,Hasskerl, Thomas,Luening, Ulrich
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p. 859 - 861
(2007/10/02)
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- Synthesis of Racemates and (+)-Enantiomers of γ-Caprolactone, γ-Dodecanolactone and δ-Hexadecanolactone, Lactonic Sex Pheromones of the Dermestid Beetle, Rove Beetle and Oriental Hornet
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A simple method based on regioselective two-step alkylation of easily-available diethyl 3-oxoglutarate (2) is described for the synthesis of racemates of the lactonic pheromones, 1a, 1b, and 1c.Their (+)-enantiomers were also synthesized by means of microbiological reduction of the intermediary keto acids.
- Naoshima, Yoshinobu,Ozawa, Hiroshi,Kondo, Hirokiyo,Hayashi, Shuichi
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p. 1431 - 1434
(2007/10/02)
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- A VERY SIMPLE SYTHESIS OF NATURAL SATURATED δ-SUBSTITUTED δ-LACTONES. THE PHEROMONE OF Vespa orientalis
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Very facile syntheses of racemic massoia lacton and the pheromone of Veapa orientialis have been achieved starting from dehydroacetic acid.
- Bacardit, Ramon,Moreno-Manas, Marcial
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