Synthesis of substituted α,β-unsaturated δ-lactones from vinyl tellurides

Oliveira, José Nuno; Freitas, Juliano Carlo Rufino; Comasseto, J. V.; Menezes, Paulo H.

doi:10.1016/j.tet.2011.02.029

Cited by 21 publications

(8 citation statements)

References 55 publications

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“…The procedures used for synthesis of the lactones 6-(but-3-enyl)-5,6-dihydro-2H-pyran-2-one (5a), 6-(allyloxymethyl)-5,6-dihydro-2H-pyran-2-one (5b), 6-ethyl-5,6-dihydro-2H-pyran-2-one (5c), 6-(phenoxymethyl)-5,6-dihydro-2H-pyran-2-one (5d), 6-phenyl-5,6-dihydro-2H-pyran-2-one (5e), and 5-phenyl-5,6-dihydro-2H-pyran-2-one (5f) are described by Barros et al (2014) and by Oliveira et al (2011). The physical and spectroscopic data are in agreement with those reported in the literature, the purity of all compounds was ≥95%, and the yields obtained were 68%, 77%, 73%, 62%, 53% and 67%, respectively.…”

Section: Synthesis Of the αβ-Unsaturated Lactonesmentioning

confidence: 99%

Effects of α,β-unsaturated lactones on larval survival and gut trypsin as well as oviposition response of Aedes aegypti

Barros

Freitas

Santos

et al. 2015

Experimental Parasitology

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Lactones are organic cyclic esters that have been described as larvicides against Aedes aegypti and as components of oviposition pheromone of Culex quinquefasciatus. This work describes the effect of six α,β-unsaturated lactones (5a-5f) on survival of A. aegypti fourth instar larvae (L4). It is also reported the effects of the lactones on L4 gut trypsin activity and oviposition behavior of A. aegypti females. Five lactones were able to kill L4 being the lactones 5a (LC50 of 39.05 ppm), 5e (LC50 of 36.30 ppm) and 5f (LC50 of 40.46 ppm) the most promising larvicides. Only the lactone 5a inhibited L4 gut trypsin activity, with an IC50 of 115.15 µg/mL. Lactones 5a, 5c, 5d and 5e did not exert deterrent or stimulatory effects on oviposition, whereas lactone 5b exhibited a strong deterrent oviposition activity. In conclusion, this work introduces new α,β-unsaturated lactones as promising alternatives to control A. aegypti dissemination. The larvicidal mechanism of the lactone 5a can involve the disruption of proteolysis at larval gut.

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Section: Synthesis Of the αβ-Unsaturated Lactonesmentioning

confidence: 99%

Effects of α,β-unsaturated lactones on larval survival and gut trypsin as well as oviposition response of Aedes aegypti

Barros

Freitas

Santos

et al. 2015

Experimental Parasitology

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“…Nevertheless, the removal of impurities by filtration through a pad of silica and trituration in boiling n-hexane proved to be advantageous to avoid the cleavage of the TMS-group in the subsequent reduction step 15 to form 5, which was accomplished in good yields of 94% (12 g) using SnCl 2 Á2H 2 O. The hexylthio-, hexylseleno-and hexyltelluro-groups were introduced by a lithium-halogen exchange and subsequent addition of either elemental sulfur or selenium and hexyl iodide to obtain 6a (2.5 g, 63%) and 6b (1.7 g, 73%) or dihexyl ditelluride 16 to obtain 6c (1.5 g, 53%).…”

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confidence: 99%

Multigram synthesis of bis[(trimethylsilyl)ethynyl]benzenes suitable for post-polymerization modification

et al. 2014

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“…In the forward direction, an activated version of 4 would be required, such that overall substitution of the hydroxyl group by the 1,3-dithiane anion could be achieved. To facilitate the synthesis of (+)-preussin B and its diastereoisomers, it was anticipated that diol 4 (X = OH) could be selectively converted into the corresponding epoxide, which would then undergo regioselective ring opening upon attack of the 1,3-dithiane anion at the least hindered (terminal) position . As such, investigations were directed toward this end (Figure ).…”

Section: Resultsmentioning

confidence: 75%

Asymmetric Syntheses of (+)-Preussin B, the C(2)-Epimer of (−)-Preussin B, and 3-Deoxy-(+)-preussin B

et al. 2016

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Efficient de novo asymmetric syntheses of (+)-preussin B, the C(2)-epimer of (-)-preussin B, and 3-deoxy-(+)-preussin B have been developed, using the diastereoselective conjugate addition of lithium (S)-N-benzyl-N-(α-methylbenzyl)amide to tert-butyl 4-phenylbut-2-enoate and diastereoselective reductive cyclizations of γ-amino ketones as the key steps to set the stereochemistry. Conjugate addition followed by enolate protonation generated the corresponding β-amino ester. Homologation using the ester functionality as a synthetic handle gave the corresponding γ-amino ketone. Hydrogenolytic N-debenzylation was accompanied by diastereoselective reductive cyclization in situ; reductive N-methylation then gave 3-deoxy-(+)-preussin B as the major diastereoisomeric product. Meanwhile, the same conjugate addition but followed by enolate oxidation with (+)-camphorsulfonyloxaziridine gave the corresponding anti-α-hydroxy-β-amino ester. α-Epimerization by oxidation and diastereoselective reduction then gave access to the corresponding syn-α-hydroxy-β-amino ester. Homologation of both of these diastereoisomeric α-hydroxy-β-amino esters gave the corresponding β-hydroxy-γ-amino ketones. N-Debenzylation and concomitant diastereoselective reductive cyclization, followed by reductive N-methylation, provided the C(2)-epimer of (-)-preussin B and (+)-preussin B as the major diastereoisomeric products, respectively. The overall yields (from phenylacetaldehyde) were 19% for 3-deoxy-(+)-preussin B over seven steps, 8% for the C(2)-epimer of (-)-preussin B over nine steps, and 7% for (+)-preussin B over eleven steps.

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Synthesis of substituted α,β-unsaturated δ-lactones from vinyl tellurides

Cited by 21 publications

References 55 publications

Effects of α,β-unsaturated lactones on larval survival and gut trypsin as well as oviposition response of Aedes aegypti

Effects of α,β-unsaturated lactones on larval survival and gut trypsin as well as oviposition response of Aedes aegypti

Multigram synthesis of bis[(trimethylsilyl)ethynyl]benzenes suitable for post-polymerization modification

Asymmetric Syntheses of (+)-Preussin B, the C(2)-Epimer of (−)-Preussin B, and 3-Deoxy-(+)-preussin B

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