110-93-0Relevant articles and documents
Asymmetric whole-cell bioreduction of an α,β-unsaturated aldehyde (citral): competing prim-alcohol dehydrogenase and C-C lyase activities
Hall, Melanie,Hauer, Bernhard,Stuermer, Rainer,Kroutil, Wolfgang,Faber, Kurt
, p. 3058 - 3062 (2006)
Asymmetric bioreduction of (E/Z)-3,7-dimethyl-2,6-octadienal (citral) using the enoate reductase activity of whole cells of yeasts, bacteria and fungi, gave the α,β-saturated aldehyde (R)-3,7-dimethyl-6-octenal (citronellal), which constitutes an important flavour component, in up to ≥95% ee. Depending on the microorganism, various amounts of prim-alcohols (nerol/geraniol and citronellol) were formed due to the action of competing prim-alcohol dehydrogenases. Citral lyase activity-leading to the loss of a C2-fragment (acetaldehyde) forming sulcatone-and oxidation of the aldehyde moiety yielding the carboxylic acid (geranic/neric acid) were detected as additional metabolic activities.
Generation of norisoprenoid flavors from carotenoids by fungal peroxidases
Zelena, Kateryna,Hardebusch, Bjoern,Huelsdau, Baerbel,Berger, Ralf G.,Zorn, Holger
, p. 9951 - 9955 (2009)
To biotechnologlcally produce norisoprenoid flavor compounds, two extracellular peroxidases (MsP1 and MsP2) capable of degrading carotenoids were isolated from the culture supematants of the basidiomycete Marasmlus scorodonlus (garlic mushroom). The encod
-SIGMATROPIC REARRANGEMENTS OF THE ACETOACETATES OF ALLYL ALCOHOLS (CARROLL REACTION) AND ALLYLPHENYL ETHERS (CLAISEN REACTION) ON THE SURFACE OF ADSORBENTS
Pogrebnoi, S. I.,Kal'yan, Yu. B.,Krimer, M. Z.,Smit, V. A.
, p. 733 - 739 (1991)
A method has been developed for effecting rearrangements of allylacetoacetates to γ,δ-unsaturated ketones (Carroll rearrangement) and allylaryl ethers to the corresponding allylphenols (Claisen rearrangement) under conditions of adsorption on aluminum oxide and silica gel.The method provides a sharp reduction of the temperature of these reactions and improvement of their efficiency.
CARROL REARRANGEMENT ON THE SURFACE OF CHROMATOGRAPHIC GRADE ALUMINA
Pogrebnoi, S. I.,Kalyan, Y. B.,Krimer, M. Z.,Smit, W. A.
, p. 4893 - 4896 (1987)
Thermolysis on the surface of AL2O3 is proposed as a mild and convenient preparative method for -sigmatropic Carrol rearrangement of acetoacetic esters of tertiary allyl alcohols into respective γ,δ-unsaturated ketones.
Biotransformation of geraniol and nerol by spores of Penicillium italicum
Demyttenaere, Jan C.R.,De Footer, Herman L.
, p. 1079 - 1082 (1996)
A simple and efficient method was developed to carry out biotransformation reactions on volatile terpenoid compounds. Both geraniol and nerol were transformed into 6-methyl-5-hepten-2-one by sporulated surface cultures of Penicillium italicum over prolonged periods (up to 2 months). The bioconversion was followed by dynamic headspace techniques. Copyright
A simple and practical phase-separation approach to the recycling of a homogeneous metathesis catalyst
Michrowska, Anna,Gulajski, Lukasz,Grela, Karol
, p. 841 - 843 (2006)
The air stable asarone-derived Ru carbene 16, a robust olefin metathesis catalyst, can be easily separated after reaction by deposition on silica gel and reused up to nine times. This procedure provides products of excellent purity with low Ru content. The Royal Society of Chemistry 2006.
Orchestration of concurrent oxidation and reduction cycles for stereoinversion and deracemisation of sec-alcohols
Voss, Constance V.,Gruber, Christian C.,Faber, Kurt,Knaus, Tanja,Macheroux, Peter,Kroutil, Wolfgang
, p. 13969 - 13972 (2008)
Black and white are opposites as are oxidation and reduction. Performing an oxidation, for example, of a sec-alcohol and a reduction of the corresponding ketone in the same vessel without separation of the reagents seems to be an impossible task. Here we show that oxidative cofactor recycling of NADP + and reductive regeneration of NADH can be performed simultaneously in the same compartment without significant interference. Regeneration cycles can be run in opposing directions beside each other enabling one-pot transformation of racemic alcohols to one enantiomer via concurrent enantioselective oxidation and asymmetric reduction employing defined alcohol dehydrogenases with opposite stereo- and cofactor-preference. Thus, by careful selection of appropriate enzymes, NADH recycling can be performed in the presence of NADP+ recycling to achieve overall, for example, deracemisation of sec-alcohols or stereoinversion representing a possible concept for a "green" equivalent to the chemical-intensive Mitsunobu inversion.
Novel polymer effect in cleavage reactions of acetals and silyl ethers in aqueous media catalyzed by a polymer-supported dicyanoketene acetal
Masaki,Yamada,Tanaka
, p. 1311 - 1313 (2001)
Deprotecting reactions of acetals including acetonides, ethylene acetals, and THP ethers of alcohols, an aldehyde, and ketones, and silyl ethers of primary and secondary alcohols were investigated using dicyanoketene acetals (DCKA) and a polymersupported DCKA as a π-acid promoter in aqueous acetonitrile and a single aqueous medium. In all reactions catalytic activity of the polymer-supported DCKA was found to be much higher than that of the molecular DCKAs and an excellent polymer effect was observed. Particularly in the deacetalization reactions in water, difference of catalytic efficiency between the polymer-supported DCKA and the molecular DCKAs was remarkable.
Synthesis of sesquiterpene polyene hydroperoxides by regio- and stereoselective transposition reactions
Fielder, Simon,Rowan, Daryl D.,Sherburn, Michael S.
, p. 12907 - 12922 (1998)
Isomeric unsaturated alcohols (8), (16), (18) and (20), on exposure to hydrogen peroxide or water in the presence of an acid catalyst, undergo exceptionally regio- and stereoselective substitution reactions to form hydroperoxide (3) and alcohol (8) respectively. E/Z isomeric ratios of transposition products indicate that the intermediate acyclic carbocations (21) and (22) are not interconverting under the reaction conditions. Practical syntheses of α-farnesene autoxidation products have been developed based on these transposition reactions.
Two-carbons homologation of methyl ketones examplified for the synthesis of citral from 6-methyl-5-hepten-2-one
Valla, Alain,Cartier, Dominique,Laurent, Alain,Valla, Benoist,Labia, Roger,Potier, Pierre
, p. 1195 - 1201 (2003)
New facile syntheses of 3,7-dimethyl-octadien-2,6-al (citral) from homologation of 6-methyl-5-hepten-2-one are reported.
