ChemInform Abstract: NATURALLY OCCURING LACTONES AND LACTAMES PART 5, HALOGENATED BETA‐KETO ESTERS AS STARTING MATERIALS FOR THE SYNTHESIS OF TETRONIC ACIDS

Svendsen, Axel; Boll, Per M.

doi:10.1002/chin.197419287

Cited by 4 publications

(5 citation statements)

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“…The synthesis commenced with bromination of methyl acetoacetate to give methyl 4-bromoacetoacetate, using conditions previously reported for the synthesis of the analogous ethyl ester (16,17). This procedure proved superior to those in earlier reports (19,20), which resulted in a higher percentage of side products.…”

Section: Resultsmentioning

confidence: 99%

“…2-Methyl-5-oxocyclopent-1-ene-1,3-dicarboxylic Acid 3-Ethyl Ester 1-Methyl Ester (4). Methyl 4-bromoacetoacetate 2 was made by the method described for synthesis of ethyl 4-bromoacetoacetate (16,17). Thus, bromine (2.6 mL, 50 mmol, in 5 mL of CHCl 3 ) was added slowly to a solution of methyl acetoacetate 1 (5.81 g, 50 mmol; Aldrich Chemical Co., Milwaukee, WI) in CHCl 3 (45 mL) at 0 °C, and the mixture was stirred overnight while gradually warming to room temperature.…”

Section: Methodsmentioning

confidence: 99%

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Synthesis and Bioassay of Racemic and Chiral trans-α-Necrodyl Isobutyrate, the Sex Pheromone of the Grape Mealybug Pseudococcus maritimus

Zou

Daane

Bentley

et al. 2010

J. Agric. Food Chem.

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A concise synthesis of the racemic form of the female-produced pheromone of the grape mealybug was developed. The synthesis was readily adapted to production of both enantiomers of the pheromone via lipase-catalyzed kinetic resolution of an intermediate in the synthesis. Replicated field trials revealed that, contrary to a preliminary report, the (R,R)- rather than the (S,S)-enantiomer is the attractive stereoisomer. Lithium aluminum hydride reduction of the insect-produced compound to alpha-necrodol followed by analysis on a chiral stationary phase GC column showed that the insect-produced material was actually an 85:15 mixture of the (R,R)- and (S,S)-enantiomers. The racemic form of the pheromone was highly attractive to male mealybugs, and in one of two field bioassays, the racemic material was significantly more attractive than the pure (R,R)-enantiomer, suggesting that the (S,S)-enantiomer might act synergistically.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Synthesis and Bioassay of Racemic and Chiral trans-α-Necrodyl Isobutyrate, the Sex Pheromone of the Grape Mealybug Pseudococcus maritimus

Zou

Daane

Bentley

et al. 2010

J. Agric. Food Chem.

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“…Synthesis of ethyl 3-oxo-5,9,13,-trimethyltetradeca-4,8,12trienoate. Ethyl 4-diethylphosphono-3-oxobutanoate (4.8 g), prepared from ethyl 4-bromoacetoacetate (6) and diethylphosphite by the method of Bodalski et al (1), was dissolved in 40 ml of dry tetrahydrofuran. This was added in portions to a suspension of NaH (1.8 g in 60 ml of dry tetrahydrofuran) at 25°C with stirring under nitrogen gas over a period of 10 min.…”

Section: Methodsmentioning

confidence: 99%

Oxidative Pathway from Squalene to Geranylacetone in Arthrobacter sp. Strain Y-11

Ikeguchi

Nihira

Kishimoto

et al. 1988

Appl Environ Microbiol

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The reaction pathway from squalene to trans-geranylacetone in Arthrobacter sp. strain Y-11 was studied. The enzyme or enzymes catalyzing squalene degradation were found to be membrane bound. Stoichiometric analysis of a cell-free system revealed that the ratio of squalene to trans-geranylacetone changed from 1:2 to 1:1 as the reaction proceeded, indicating two steps in geranylacetone formation. The initial step was found to be oxygenase catalyzed, from the absolute requirement for molecular oxygen in geranylacetone formation and the incorporation of 180 into geranylacetone under 1802 atmosphere. By using [3H]squalene as the substrate, we detected an intermediate in the pathway and identified it as 5,9,13-trimethyltetradeca-4,8,12-trienoic acid by mass spectrometry, infrared spectrometry, nuclear magnetic resonance spectrometry, and chemical synthesis. We deduced that squalene was first oxidatively cleaved to geranylacetone and the intermediate, and that the intermediate was further metabolized to geranylacetone. We also synthesized some of the presumptive metabolites, such as 4,8,12-trimethyltrideca-4,8,12-trien-2-one, and confirmed that they served as active precursors for geranylacetone formation. Based on these lines of evidence, we present here the pathway from squalene to trans-geranylacetone in Arthrobacter sp. strain Y-11.

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“…The 4-substituted-3-oxobutyric acid ethyl esters 2a-e and their brominated forms 3a-e were prepared according to previously methods reported by Hamz et al 2005 andSvendsen andBoll 1973 , respectively. All reactions were conducted under a stream of nitrogen.…”

Section: Synthesis Of Thiazole Derivativesmentioning

confidence: 99%

Synthesis of Thiazole Derivatives and Evaluation of Their Antiamoebic Activity and Cytotoxicity

et al. 2013

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Five ethyl 5-alkyl-2-amino-1,3-thiazol-4-yl acetates designated compounds 4a-e incorporating octyl, decyl, dodecyl, tetradecyl, and hexadecyl alkyl chains, respectively, were prepared by reacting 4-alkyl-4-bromo-3-oxobutyric acid ethyl esters 3a-e with thiourea in dried acetonitrile. Compounds 3a-e were synthesized by reacting alkylated ethyl acetoacetates with bromine. The newly synthesized compounds were characterized by mass spectrometry, NMR, and elemental analysis. Compounds 4a-c demonstrated good in vitro antiamoebic activity against Acanthamoeba polyphaga exposed to 10 mg L 1 for 6 h at 28 . Compound 4b showed the highest antiamoebic activity among the tested compounds, comparable to that of chlorhexidine dihydrochloride CHX , decreasing the number of viable cells to below the detection limit of 1 cell mL 1 . The activity of compounds 4a and 4c was similar to that of the commercial antifungal agent fluconazole Flu . The cytotoxic and hemolytic activity of the compounds was assayed against human neonate dermal fibroblasts and sheep erythrocytes, respectively. Compounds 4a-c were less cytotoxic than Flu and CHX. Our results suggest that compound 4b, which is composed of a 2-amino-thiazole attached to a decyl group and an ethyl ester moiety, is a particularly safe and effective alternative amoebicidal agent.

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ChemInform Abstract: NATURALLY OCCURING LACTONES AND LACTAMES PART 5, HALOGENATED BETA‐KETO ESTERS AS STARTING MATERIALS FOR THE SYNTHESIS OF TETRONIC ACIDS

Cited by 4 publications

References 1 publication

Synthesis and Bioassay of Racemic and Chiral trans-α-Necrodyl Isobutyrate, the Sex Pheromone of the Grape Mealybug Pseudococcus maritimus

Synthesis and Bioassay of Racemic and Chiral trans-α-Necrodyl Isobutyrate, the Sex Pheromone of the Grape Mealybug Pseudococcus maritimus

Oxidative Pathway from Squalene to Geranylacetone in Arthrobacter sp. Strain Y-11

Synthesis of Thiazole Derivatives and Evaluation of Their Antiamoebic Activity and Cytotoxicity

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