- Diastereoselective synthesis of (±)-trichodiene and (±)-trichodiene-D3as analytical standards for the on-site quantification of trichothecenes
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The ubiquitous Fusarium genus is responsible for the spoilage of vast amounts of cereals and fruits. Besides the economic damage, the danger to human and animal health by the concomitant exposure to mycotoxins represents a serious problem. A large number of Fusarium species produce a variety of different mycotoxins of which the class of trichothecenes are of particular importance due to their toxicity. Being identified as the common volatile precursor during the biosynthesis of trichothecenes, (-)-trichodiene (TD) is considered to be a biomarker for the respective mycotoxin content in food samples. We postulated that the development of a non-invasive, on-site GC-IMS method for the quantification of (-)-trichodiene supplemented with a stationary SIDA headspace GC-MS reference method would allow circumventing the laborious and expensive analyses of individual trichothecenes in large cereal samples. In this work we present the syntheses of the required native calibration standard and an isotope labeled (TD-D3) internal standard. This journal is
- Gebauer, Julian,Koch, Matthias,Sebald, Michael A.
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p. 9872 - 9879
(2021/12/07)
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- Studies toward the generation of functionalized quaternary carbon centers relying on wittig and wittig-still allylic ether anionic transpositions
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Although the [2,3]-Wittig and Wittig-Still rearrangements have long been known, their application in the generation of quaternary carbon centers in carbocyclic ring systems is sparse. Model studies utilizing this strategy and possible mechanisms are discussed herein. Unprecedented examples of an α-elimination pathway from stannylmethyl allyl ethers as a major undesired product in some Wittig-Still rearrangements are reported.
- Hanessian, Stephen,Dorich, Stephane,Chattopadhyay, Amit Kumar,Bueschleb, Martin
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p. 8915 - 8921
(2013/09/24)
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- Formal total synthesis of (±)-trichodiene via Claisen rearrangement and Robinson annulation
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A facile formal total synthesis of (±)-trichodiene was achieved by employing Claisen rearrangement and Robinson annulation as synthetic key strategies.
- Jung, Jae-Chul,Jung, Young-Jo,Park, Oee-Sook
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experimental part
p. 293 - 297
(2009/01/31)
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- COMPOUNDS AND METHODS FOR THE TREATMENT OF VIRUSES AND CANCER
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The present invention relates to compounds according to the formula I: Where Ra is H or an optionally OH-substituted C1-C3 alkyl; R1 is OR1, an optionally substituted C4-12 carbocyclic group which may be saturated or unsaturated (including aromatic) or an optionally substituted heterocyclic group; R1 is an optionally substituted C1-C14 hydrocarbyl group or an optionally substituted heterocyclic group;; R2 , R3 and R4 are each independently H, an optionally substituted C1-C4 alkyl group (preferably CH3, CH2CH3 or CF3), halogen (preferably F, Cl, Br), OR, CN, NO2, a C1-C6 thioether, a C1-C6 thioester group, an optionally substituted CO2R group, an optionally substituted COR group or an optionally substituted OCOR group (preferably R4 is H); R is H or an optionally substituted C1-C6 alkyl group; RHET is an optionally substituted heterocyclic group; and pharmaceutically acceptable salts, solvates or polymorphs thereof.
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Page/Page column 66-67
(2010/11/26)
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- (2-hydroxy)ethyl-thioureas useful as modulators of alpha2B adrenergic receptors
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Compounds of formula (i) and of formula (ii) wherein the symbols have the meaning disclosed in the specification, specifically or selectively modulate α2B and/or α2C adrenergic receptors in preference over α2A adrenergic receptors, and as such are useful for alleviating chronic pain and allodynia and have no or only minimal cardivascular and/or sedatory activity.
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- Asymmetric synthesis of (-)-trichodiene. Generation of vicinal stereogenic quaternary centers via the thio-Claisen rearrangement
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The use of chiral bicyclic lactams, in their thiocarbonyl form 9, has been shown to serve as important intermediates for producing α-quaternary alkyl derivatives 8, which were readily transformed into the title compound (-)-1. The reversibility of the thi
- Lemieux, René M.,Meyers
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p. 5453 - 5457
(2007/10/03)
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- Stereoselective Reduction of α-Iodospirolactones. Total Synthesis of (+/-)-Liguloxide.
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Radical-mediated reduction of α-methyl-α-iodospirolactones yielded trans-α-methylspirolactones selectively.This reaction was used in the total synthesis of (+/-)-liguloxide.
- Lee, Eun,Lee, Dae Sung,Choi, Yoon Whan,Lee, Kwang Ho
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p. 6673 - 6676
(2007/10/02)
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- General Method of Synthesis of Cyclopentanoid Terpenic Acids. Stereocontrolled Total Syntheses of (+/-)Isocomenic Acid and (+/-)-Epiisocomenic Acid
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(4β,8α)-1α,2,4β-Trimethyl-9α-carboxytricyclo4,8>undec-2-ene (1, isocomenic acid) and (4β,8α)-1α,2,4β-trimethyl-9β-carboxytricyclo4,8>undec-2-ene (28, epiisocomenic acid) were prepared in 10 steps from ester 13.The internal cyclopropanation of exocyclic acrylates and the subsequent vinylcyclopropane-cyclopentene rearrangement were used in an efficient synthesis of a key intermediate, triquinane 23, containing all of the contiguous quarternary centers.The utilization of abnormal Reformatsky reaction of 4-bromocrotonates with keto esters served in the preparation of important precursors to the cyclopentene annulation sequence, the lactone 15, and the dienic acid 19.Hydrogenation of 23 produced the keto ester 25a, which was converted in three steps to either 1 or 28 with complete control of stereochemistry.Carbon-13 data are reported for all intermediates.A total of eight natural products are accessible in a stereocontrolled fashion from keto ester 25a.The generality of this method is thus addressed in the context of system-oriented design of synthesis of cyclopentanoid terpenes.
- Short, Robert P.,Revol, Jean-Marc,Ranu, B. C.,Hudlicky, Tomas
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p. 4453 - 4461
(2007/10/02)
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- Reactions of the Formaldehyde-Trimethylaluminum Complex with Alkenes
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Reaction of CH2O*Me3Al with electron-rich alkenes gives a zwitterion that reacts further to give homoallylic alcohols (ene adducts), allylic alcohols, and the product of cis addition of a hydroxymethyl and a methyl group to the double bond.The stereochemistry and effect of alkene structure on the nature of the reaction are examined.
- Snider, Barry B.,Cordova, Robert,Price, Robert T.
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p. 3643 - 3646
(2007/10/02)
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- Synthesis of dl-3-Hydroxycuparene by a Claisen Rearrangement of Allyl Aryl Ether
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The Claisen rearrangement of 1-methyl-2-cyclopentene in N,N-dimethylformamide gave 5-methyl-2-(1-methyl-2-methylenecyclopentyl)phenol (5) via its trimethylsilyl ether. The methylation of 5, followed by a Simmons-Smith reaction and by the catalytic hydrogenolysis, afforded 3-hydroxycuparene.
- Inouye, Yoshinobu,Inomata, Satoru,Ishihara, Yasumasa,Kakisawa, Hiroshi
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p. 208 - 211
(2007/10/02)
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