Total synthesis of elansolids B1 and B2

Wang, Liangliang; Kirschning, Andreas

doi:10.3762/bjoc.13.124

Cited by 6 publications

(8 citation statements)

References 13 publications

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“…The elansolids are a family of polyketide antibiotics from the gliding bacteria Chitinophaga sancti. Initially, alongside the original atropoisomers elansolids A1/A2 ( 2 ), the derivatives elansolid B1 ( 3 ), B2 ( 4 ), and B3 (not shown) were identified in the bacterial fermentation extract (Figure ). − …”

Section: Categories Of Nonenzymatic Mechanismssupporting

confidence: 66%

Nonenzymatic Reactions in Natural Product Formation

et al. 2022

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Biosynthetic mechanisms of natural products primarily depend on systems of protein catalysts. However, within the field of biosynthesis, there are cases in which the inherent chemical reactivity of metabolic intermediates and substrates evades the involvement of enzymes. These reactions are difficult to characterize based on their reactivity and occlusion within the milieu of the cellular environment. As we continue to build a strong foundation for how microbes and higher organisms produce natural products, therein lies a need for understanding how protein independent or nonenzymatic biosynthetic steps can occur. We have classified such reactions into four categories: intramolecular, multicomponent, tailoring, and light-induced reactions. Intramolecular reactions is one of the most well studied in the context of biomimetic synthesis, consisting of cyclizations and cycloadditions due to the innate reactivity of the intermediates. There are two subclasses that make up multicomponent reactions, one being homologous multicomponent reactions which results in dimeric and pseudodimeric natural products, and the other being heterologous multicomponent reactions, where two or more precursors from independent biosynthetic pathways undergo a variety of reactions to produce the mature natural product. The third type of reaction discussed are tailoring reactions, where postmodifications occur on the natural products after the biosynthetic machinery is completed. The last category consists of light-induced reactions involving ecologically relevant UV light rather than high intensity UV irradiation that is traditionally used in synthetic chemistry. This review will cover recent nonenzymatic biosynthetic mechanisms and include sources for those reviewed previously.

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Section: Categories Of Nonenzymatic Mechanismssupporting

confidence: 66%

Nonenzymatic Reactions in Natural Product Formation

et al. 2022

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“…Concerning the construction of the chiral polyene chain, Kirschning planned to use the (2 S ,3 S ) chirality within aldehydes 414 (representing the fragment C7–C11) to control the absolute R -configuration of the newly formed stereogenic center at C7, with the aid of the Yamamoto protocol. 296 − 298 …”

Section: Vinylogous Esters and Lactonesmentioning

confidence: 99%

“… The core structure of these natural polyketides features a bicyclo[4.3.0]nonane unit embedding a chiral polyene chain resulting in a macrolactone core in elansolids A1 and A2 or its linear seco -acid form in elansolids B1 and B2. Concerning the construction of the chiral polyene chain, Kirschning planned to use the (2 S ,3 S ) chirality within aldehydes 414 (representing the fragment C7–C11) to control the absolute R -configuration of the newly formed stereogenic center at C7, with the aid of the Yamamoto protocol. − …”

Section: Vinylogous Esters and Lactonesmentioning

confidence: 99%

New Developments of the Principle of Vinylogy as Applied to π-Extended Enolate-Type Donor Systems

et al. 2020

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The principle of vinylogy states that the electronic effects of a functional group in a molecule are possibly transmitted to a distal position through interposed conjugated multiple bonds. As an emblematic case, the nucleophilic character of a π-extended enolate-type chain system may be relayed from the legitimate α-site to the vinylogous γ, ε, ..., ω remote carbon sites along the chain, provided that suitable HOMO-raising strategies are adopted to transform the unsaturated pronucleophilic precursors into the reactive polyenolate species. On the other hand, when “unnatural” carbonyl ipso -sites are activated as nucleophiles (umpolung), vinylogation extends the nucleophilic character to “unnatural” β, δ, ... remote sites. Merging the principle of vinylogy with activation modalities and concepts such as iminium ion/enamine organocatalysis, NHC-organocatalysis, cooperative organo/metal catalysis, bifunctional organocatalysis, dicyanoalkylidene activation, and organocascade reactions represents an impressive step forward for all vinylogous transformations. This review article celebrates this evolutionary progress, by collecting, comparing, and critically describing the achievements made over the nine year period 2010–2018, in the generation of vinylogous enolate-type donor substrates and their use in chemical synthesis.

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“…The total chemical synthesis of elansolid B1 (4) 26 was followed by the second-generation total synthesis of the same compound and the rst synthesis of elansolid B2 (5). 27 Further studies to elucidate the biosynthesis of elansolids 28,29 revealed a further polyketide, 20-deoxy-elansolid B1 (10), with activity similar to elansolid A2 (2), showing that the hydroxyl group at C20 is not essential for antibacterial activity. 28…”

Section: Elansolidsmentioning

confidence: 99%