Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

TESOTf-induced rearrangement of quinols. Efficient construction of the fully functionalized carbon skeleton of the griseusins by a divergent-reconvergent approach.

ABSTRACT: [reaction: see text] The "reverse polarity" or "umpolung" strategy for the total synthesis of aryl C-glycosides was developed in the context of the antibiotic (-)-griseusin B. Although a key reaction in a model sequence for the total synthesis produced two structurally divergent products, both were converted to the same advanced model intermediate that contains the complete carbon skeleton and (except for the extraneous oxygen substituent in the model series) the functional group pattern of the griseusins.

SUBMITTER: Parker KA

PROVIDER: S-EPMC2668545 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

TESOTf-induced rearrangement of quinols. Efficient construction of the fully functionalized carbon skeleton of the griseusins by a divergent-reconvergent approach.

Parker Kathlyn A KA Mindt Thomas L TL Koh Yung-hyo YH

Organic letters 20060401 9

[reaction: see text] The "reverse polarity" or "umpolung" strategy for the total synthesis of aryl C-glycosides was developed in the context of the antibiotic (-)-griseusin B. Although a key reaction in a model sequence for the total synthesis produced two structurally divergent products, both were converted to the same advanced model intermediate that contains the complete carbon skeleton and (except for the extraneous oxygen substituent in the model series) the functional group pattern of the ...[more]

PMID: 16623544

Similar Datasets

Efficient construction of the securine A carbon skeleton.

Project description:Securamine A is a structurally intriguing alkaloid possessing a pyrroloindole core joined via a modified isoprene subunit to a functionalized imidazole ring. Recent synthetic efforts in this laboratory have resulted in the efficient construction of key lactone 36, which undergoes tandem azide reduction/ring expansion to macrolactam 37. Macrolactam 37 possesses the complete macrocyclic core of securamine A.

| S-EPMC514433 | biostudies-other

L-Ascorbate Biosynthesis Involves Carbon Skeleton Rearrangement in the Nematode Caenorhabditis elegans.

Project description:Ascorbate (AsA) is required as a cofactor and is widely distributed in plants and animals. Recently, it has been suggested that the nematode Caenorhabditis elegans also synthesizes AsA. However, its biosynthetic pathway is still unknown. To further understand AsA biosynthesis in C. elegans, we analyzed the incorporation of the 13C atom into AsA using gas chromatography-mass spectrometry (GC-MS) in worms fed with D-Glc (1-13C)-labeled Escherichia coli. GC-MS analysis revealed that AsA biosynthesis in C. elegans, similarly to that in mammalian systems, involves carbon skeleton rearrangement. The addition of L-gulono-1,4-lactone, an AsA precursor in the mammalian pathway, significantly increased AsA level in C. elegans, whereas the addition of L-galactono-1,4-lactone, an AsA precursor in the plant and Euglena pathway, did not affect AsA level. The suppression of E03H4.3 (an ortholog of gluconolactonase) or the deficiency of F54D5.12 (an ortholog of L-gulono-1,4-lactone oxidase) significantly decreased AsA level in C. elegans. Although N2- and AsA-deficient F54D5.12 knockout mutant worm (tm6671) morphologies and the ratio of collagen to non-collagen protein did not show any significant differences, the mutant worms exhibited increased malondialdehyde levels and reduced lifespan compared with the N2 worms. In conclusion, our findings indicate that the AsA biosynthetic pathway is similar in C. elegans and mammals.

| S-EPMC7463950 | biostudies-literature

Functionalized carbon nanotube toxicity in Arabidopsis leaves

Project description:Polyethilenimine (PEI) functionalized single walled carbon nanotubes (SWNTs) and carbon-based nanomaterials enable delivery of DNA and RNA in plants. Given the broad-scale use of PEI-functionalized nanomaterials in plants, we sought to investigate the reaction of plant tissues to treatment with PEI-SWNTs and pristine SWNTs. To this end, we infiltrated Arabidopsis thaliana leaves with pristine single walled carbon nanotubes used in RNA silencing applications (SWNTs) and polyethyleneimine-functionalized SWNTs used for plasmid DNA delivery (PEI-SWNTs). We used Arabidopsis as it is a well characterized model plant, for which genomic and detailed gene function information is readily available. To minimize the effects caused by the introduction of exogenous nucleic acids, in SWNT preparations we used single stranded RNA targeting Green Fluorescent Protein (GFP) with no target sequence in the Arabidopsis genome, and a plasmid that expresses GFP in PEI-SWNT preparations. For our experiments herein, we used ~25-50 fold higher concentrations of SWNTs and PEI-SWNTs compared to standard concentrations used in biomolecule delivery assays. Water-infiltrated plant leaves served as a negative control to distinguish between the SWNT-specific response and the response to the infiltration process itself. We performed RNA sequencing (RNA-seq) with RNA extracted from leaves two days after infiltration to identify changes in the leaf transcriptomic profile in response to the three treatments, compared to non-infiltrated leaves.

2021-12-29 | GSE172278 | GEO

An efficient and general approach to beta-functionalized ketones.

Project description:[structure: see text]. The oxidation of selected anions (N3-, SCN-, I-, and Br-) by ceric ammonium nitrate (CAN) in the presence of substituted cyclopropyl alcohols provides a novel approach to beta-functionalized ketones. The protocol has a number of advantages including short reaction times, ease of reagent handling, and mild, neutral reaction conditions. Overall, this method provides an alternative pathway to important starting materials and intermediates in organic synthesis.

| S-EPMC2593908 | biostudies-literature

Construction of hydroxyl-functionalized hyper-crosslinked networks from polyimide for highly efficient iodine adsorption.

Project description:The rapid development of nuclear energy posed a great threat to the environment and human health. Herein, two hydroxyl-functionalized hyper-crosslinked polymers (PIHCP-1 and PIHCP-2) containing different electron active sites have been synthesized via Friedel-Crafts alkylation reaction of the polyimides. The resulting polymers showed a micro/mesoporous morphology and good thermal and chemical stability. Rely on the high porosity and multi-active sites, the PIHCPs show an ultrahigh iodine uptake capacity reached 6.73 g g-1 and the iodine removal efficiency from aqueous solution also reaches 99.7%. Kinetic analysis demonstrates that the iodine adsorption on PIHCPs was happened on the heterogeneous surfaces in the form of multilayer chemisorption. Electrostatic potential (ESP) calculation proves the great contribution of hydroxyl groups on the iodine capture performance. In addition, the iodine capture efficiency of both adsorbents can be maintained over 91% after four cyclic experiments which ensures their good recyclability for further practical applications.

| S-EPMC10847683 | biostudies-literature

Divergent Synthesis of Functionalized Indenopyridin-2-ones and 2-Pyridones via Benzyl Group Transfer: Two Cases of Aza-semipinacol-Type Rearrangement.

Project description:The synthesis of bromo-substituted indeno[1,2-b]pyridin-2-ones and 3-iodo-5-benzyl-substituted 2-pyridones, starting from easily available 6-benzyl-3,6-dihydropyridin-2(1H)-ones, triggered by NBS and NIS, respectively, is described. In both syntheses, a transfer of a benzyl group from the C6 to C5 lactam position occurred, indicating a novel aza-semipinacol-type rearrangement. Identification of intermediate compounds in both transformations supported the proposed reaction mechanisms. In the process of checking the scope of the method's application, functionalized indeno[1,2-b]pyridin-2-ones and 5-benzyl-2-pyridones were obtained.

| S-EPMC9706813 | biostudies-literature

Enantioselective Construction of Acyclic Quaternary Carbon Stereocenters: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Amide Enolates.

Project description:We report a divergent and modular protocol for the preparation of acyclic molecular frameworks containing newly created quaternary carbon stereocenters. Central to this approach is a sequence composed of a (1) regioselective and -retentive preparation of allyloxycarbonyl-trapped fully substituted stereodefined amide enolates and of a (2) enantioselective palladium-catalyzed decarboxylative allylic alkylation reaction using a novel bisphosphine ligand.

| S-EPMC5555155 | biostudies-literature

Construction of the 5,6,7-tricyclic skeleton of lancifodilactone F.

Project description:We report herein the synthesis of a fully functionalized B,C,D-ring system of lancifodilactone F. The key transformations involve an arene-olefin meta-photocycloaddition reaction and a palladium-catalyzed oxidative C-C cleavage reaction to establish its B,C-rings.

| S-EPMC4472376 | biostudies-literature

Fully Inkjet-Printed Biosensors Fabricated with a Highly Stable Ink Based on Carbon Nanotubes and Enzyme-Functionalized Nanoparticles.

Project description:Enzyme inks can be inkjet printed to fabricate enzymatic biosensors. However, inks containing enzymes present a low shelf life because enzymes in suspension rapidly lose their catalytic activity. Other major problems of printing these inks are the non-specific adsorption of enzymes onto the chamber walls and stability loss during printing as a result of thermal and/or mechanical stress. It is well known that the catalytic activity can be preserved for significantly longer periods of time and to harsher operational conditions when enzymes are immobilized onto adequate surfaces. Therefore, in this work, horseradish peroxidase was covalently immobilized onto silica nanoparticles. Then, the nanoparticles were mixed into an aqueous ink containing single walled carbon nanotubes. Electrodes printed with this specially formulated ink were characterized, and enzyme electrodes were printed. To test the performance of the enzyme electrodes, a complete amperometric hydrogen peroxide biosensor was fabricated by inkjet printing. The electrochemical response of the printed electrodes was evaluated by cyclic voltammetry in solutions containing redox species, such as hexacyanoferrate (III/II) ions or hydroquinone. The response of the enzyme electrodes was studied for the amperometric determination of hydrogen peroxide. Three months after the ink preparation, the printed enzyme electrodes were found to still exhibit similar sensitivity, demonstrating that catalytic activity is preserved in the proposed ink. Thus, enzyme electrodes can be successfully printed employing highly stable formulation using nanoparticles as carriers.

| S-EPMC8303974 | biostudies-literature

Assembling the carbon skeleton of A-74528.

Project description:The 2'-phosphodiesterase inhibitor A-74528, which combines an intriguing biosynthesis with unusual biological activity, is one of the most complex type II polyketides. As a synthetic target, it represents a significant challenge due to its size but also due to a unique carbon skeleton that features a hexacarbocyclic core with an appended pyrone. Here we report our efforts toward the synthesis of A-74528, which culminated in the construction of the full carbon skeleton and the correct installation of all but one stereocenter. Our strategy employs a molybdenum-catalyzed branched allylation to establish the central quaternary carbon and relies on establishing the remaining stereocenters in a substrate-controlled manner. Carbocycles were established using a spiro epoxide annulation, a 1,3-dipolar cycloaddition, followed by an aldol condensation, and a gold-catalyzed hydroarylation. The pyrone was appended to an aldehyde branching off the quaternary stereocenter by a one-carbon homologation and Mukaiyama aldol addition.

| S-EPMC9297437 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data