Synthesis and characterization of enantiomers of 5- and 6-methyloctanoic acids

Sonnet, Philip E.; Gazzillo, Joseph A.; Dudley, Robert L.; Boswell, Richard T.

doi:10.1016/0009-3084(90)90013-h

Cited by 8 publications

(7 citation statements)

References 19 publications

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“…A closely related fatty acid in the S configuration has a reported optical rotation of [α] D = + 8.0 (Sonnet et al, 1990), while 5 has a measured rotation of [α] D = + 9.0. In addition, the major isomers of related compounds 6 and 11 are in the S configuration.…”

Section: Resultsmentioning

confidence: 99%

A Bacterial Source for Mollusk Pyrone Polyketides

Lin

Torres

Ammon

et al. 2013

Chemistry & Biology

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Summary In the oceans, toxic secondary metabolites often protect otherwise poorly defended, soft-bodied invertebrates such as shell-less mollusks from predation. The origins of these metabolites are largely unknown, but many of them are thought to be made by symbiotic bacteria. In contrast, mollusks with thick shells and toxic venoms are thought to lack these secondary metabolites due to reduced defensive needs. Here, we show that heavily defended cone snails also occasionally contain abundant secondary metabolites, γ-pyrones known as nocapyrones, and that these pyrones are synthesized by symbiotic bacteria. This study shows that symbiotic bacteria can produce metabolites isolated from gastropod mollusks. The symbiotic bacteria, Nocardiopsis alba CR167, are closely related to potentially widespread actinomycetes that we propose to be casual symbionts of invertebrates on land and in the sea. The natural roles of nocapyrones are not known, but they are active in neurological assays at low micromolar levels, revealing that mollusks with external shells are an overlooked source of secondary metabolite diversity.

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Section: Resultsmentioning

confidence: 99%

A Bacterial Source for Mollusk Pyrone Polyketides

Lin

Torres

Ammon

et al. 2013

Chemistry & Biology

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“…Glacial acetic acid was also purchased from Aldrich. [ S ]‐6‐Methyloctanoic acid (6‐MOA) was prepared by Jones oxidation of the corresponding alcohol (37,38). 1 H NMR (400 MHz, CDCl 3 ) δ 0.9 (m, 6 H), 1.1.…”

Section: Methodsmentioning

confidence: 99%

“…13 C NMR (CDCl 3 ) δ 11.37, 19.14, 25.00, 26.65, 26.89, 29.48, 34.09, 34.35, 180.07). [α] D 20 = + 9.0° (c 1.02, CHCl 3 ), lit + 8.9° (38). [ S ]‐7‐Methyloctanoic acid (7‐MOA) was prepared from the corresponding bromide via Grignard reaction quenched with CO 2 (39).…”

Section: Methodsmentioning

confidence: 99%

Synthesis and characterization of the colistin peptide polymyxin E1 and related antimicrobial peptides

Kline

Holub

Therrien

et al. 2001

The Journal of Peptide Research

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Two strategies were developed to synthesize the acylated cyclic peptides know as polymyxins. Synthesis of polymyxin E1 and several analogs enabled us to evaluate the minimum inhibitory concentration of individual compounds against Gram-negative bacteria. In this study we also report the first identification of two component peptides in the complex polymyxin fermentation product colistin, a Thr2Ser isoform and an acyl group isomer. Both of these peptides, as well as a known component peptide, Leu7Ile, were similar to polymyxin E1 in potency, suggesting that conservative mutations in the colistin family are functionally inconsequential. In contrast, the acyclic analogs of all of these peptides were inactive, indicating that the characteristic lariat structure of the polymyxins is necessary for antimicrobial activity.

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“…The p -methylbenzyl (MBn) group is an uncommon analogue of the benzyl protecting group family. It has been used for the protection of phenols and carbohydrates, and its deprotection proceeds similar to that of the Bn group under hydrogenolysis − ,, and with the use of a Lewis acid. , Additionally, a trifluoroacetic acid (TFA) cocktail (2% each of H 2 O, ethanedithiol, and triisopropylsilane in TFA) enables its removal, indicating that it is weaker than the Bn group (Scheme a). Further, results suggesting potential oxidative removal of the MBn group have been reported (Scheme b,c), − highlighting the possibilities for deprotection of this group using multiple approaches.…”

mentioning

confidence: 99%

“…The treatment of 3c and 3i with hydrogen gas and palladium on carbon gave 4c′ and 4i in both excellent yields, along with the removal of the MBn ether in the case of 3c . Hydrogenolysis of MBn groups typically requires high pressures, , and it is noteworthy that the hydrogenolysis of 3c and 3i proceeded smoothly under an atmospheric pressure of hydrogen.…”

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confidence: 99%

p-Methylbenzyl Group: Oxidative Removal and Orthogonal Alcohol Deprotection

et al. 2019

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We describe the practical removal of pmethylbenzyl (MBn) protections of alcohols by treatment with 2,3-dichloro-5,6-dicyano-p-benzoquinone. When a molecule bears benzyl and MBn groups, the oxidant selectively removes the latter groups. Further, the MBn groups tolerate ceric ammonium nitrate, resulting in chemoselective removal of the p-methoxybenzyl group in the presence of the MBn groups. These orthogonal alcohol deprotections would provide novel synthetic strategies of organic compounds.

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Synthesis and characterization of enantiomers of 5- and 6-methyloctanoic acids

Cited by 8 publications

References 19 publications

A Bacterial Source for Mollusk Pyrone Polyketides

A Bacterial Source for Mollusk Pyrone Polyketides

Synthesis and characterization of the colistin peptide polymyxin E1 and related antimicrobial peptides

p-Methylbenzyl Group: Oxidative Removal and Orthogonal Alcohol Deprotection

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