10138-44-0Relevant articles and documents
Characterization of Aroma-Active Compounds in Italian Tomatoes with Emphasis on New Odorants
Kreissl, Johanna,Schieberle, Peter
, p. 5198 - 5208 (2017)
An aroma distillate was prepared by solvent extraction and subsequent SAFE distillation from Italian vine-ripe tomatoes eliciting an intense overall aroma. Application of gc/olfactometry and the aroma extract dilution analysis revealed 44 odor-active compounds, 42 of which could be identified. The highest odor activity value of 2048 was established for the green, grassy (Z)-3-hexenal, the metallic smelling trans-4,5-epoxy-(E)-2-decenal, the potato-like 3-(methylthio)propanal, and the caramel-like 4-hydroxy-2,5-dimethyl-3(2H)-furanone. Of the further odorants, 13 compounds have previously not been reported as tomato odorants. Although most of these showed lower FD-factors, in particular, the coconut/dill-like smelling wine lactone ((3S,3aS,7aR)-3a,4,5,7a-tetrahydro-3,6-dimethylbenzofuran-2(3H)-one) appeared with a quite high FD factor. In addition, a fruity, almond-like odorant (6) with an FD factor of 1024 was detected. By application of high resolution mass spectrometry and polarity considerations, the structure of a methyl-2-ethoxytetrahydropyran isomer was suggested for 6. Four of the five possible isomers, the 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-2-ethoxytetrahydropyran were synthesized and showed similar mass spectrometric patterns. However, these were excluded by their different retention indices. Although the synthesis of the remaining 2-methyl-2-ethoxytetrahydropyran resulted in only small yields, which were not sufficient for NMR measurements, this structure is very likely for 6. This compound was never reported as a food constituent before. Finally, quantitation of 23 odorants by stable isotope dilution assays allowed for the preparation of an aroma recombinate resembling the overall aroma of the tomatoes.
Kinetic effects in water and ethylene glycol. Application to high pressure organic synthesis
Jenner, Gerard,Salem, Ridha Ben
, p. 203 - 207 (2000)
The kinetic effect of various Diels-Alder and Michael reactions is studied in water and ethylene glycol vs. organic solvents. The rate enhancement is considerable in water, much less in ethylene glycol. It is proposed that strong solvophobic interactions operate in water whereas the kinetic results in glycol are best explained by hydrogen bonding and polarity effects. From a synthetic point of view, use of the properties of water (hydrophobic interactions) or ethylene glycol (ionogenic medium) associated with the kinetic effect of high pressure may constitute an interesting multiactivation method to increase chemical reactivity. Examples of triactivation (high pressure catalytic Diels-Alder reactions in ethylene glycol) are given.
Lanthanide catalysts for the hetero Diels-Alder reaction: Effect of ligand structure and acidity
Spine,Clouston,Berg
, p. 1047 - 1054 (2007/10/03)
A series of yttrium, ytterbium, and lanthanum hexa- or heptacoordinate complexes were prepared and their catalytic activities tested in the hetero Diels-Alder reaction between crotonaldehyde and ethyl vinyl ether. It was found that a pKa below
