Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Unified Approach for the Enantioselective Synthesis of the Brominated Chamigrene Sesquiterpenes.

ABSTRACT: The brominated chamigrene sesquiterpenes constitute a large subclass of bromocyclohexane-containing natural products, yet no general enantioselective strategy for the synthesis of these small molecules exists. Herein we report a general strategy for accessing this family of secondary metabolites, including the enantioselective synthesis of (-)-?- and (-)-ent-?-bromochamigrene, (-)-dactylone, and (+)-aplydactone. Access to these molecules is enabled by a stereospecific bromopolyene cyclization initiated by the solvolysis of an enantiomerically enriched vicinal bromochloride.

SUBMITTER: Burckle AJ

PROVIDER: S-EPMC5505624 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

A Unified Approach for the Enantioselective Synthesis of the Brominated Chamigrene Sesquiterpenes.

Burckle Alexander J AJ Vasilev Vasil H VH Burns Noah Z NZ

Angewandte Chemie (International ed. in English) 20160810 38

The brominated chamigrene sesquiterpenes constitute a large subclass of bromocyclohexane-containing natural products, yet no general enantioselective strategy for the synthesis of these small molecules exists. Herein we report a general strategy for accessing this family of secondary metabolites, including the enantioselective synthesis of (-)-α- and (-)-ent-β-bromochamigrene, (-)-dactylone, and (+)-aplydactone. Access to these molecules is enabled by a stereospecific bromopolyene cyclization in ...[more]

PMID: 27506430

Similar Datasets

Anti-<i>Acanthamoeba</i> Activity of Brominated Sesquiterpenes from <i>Laurencia johnstonii</i>.

Project description:Focused on our interest to develop novel antiparasistic agents, the present study was aimed to evaluate the biological activity of an extract of Laurencia johnstonii collected in Baja California Sur, Mexico, against an Acantamoeba castellanii Neff strain. Bioassay-guided fractionation allowed us to identify the amoebicidal diastereoisomers ?-bromocuparane (4) and ?-isobromocuparane (5). Furthermore, bromination of the inactive laurinterol (1) and isolaurinterol (2) yielded four halogenated derivatives, (6)?(9), which improved the activity of the natural sesquiterpenes. Among them, the most active compound was 3?-bromojohnstane (7), a sesquiterpene derivative which possesses a novel carbon skeleton johnstane.

| S-EPMC6266398 | biostudies-literature

Enantioselective total synthesis of brevetoxin A: unified strategy for the B, E, G, and J subunits.

Project description:Brevetoxin A is a decacyclic ladder toxin that possesses 5-, 6-, 7-, 8-, and 9-membered oxacycles, as well as 22 tetrahedral stereocenters. Herein, we describe a unified approach to the B, E, G, and J rings based upon a ring-closing metathesis strategy from the corresponding dienes. The enolate technologies developed in our laboratory allowed access to the precursor acyclic dienes for the B, E, and G medium-ring ethers. The strategies developed for the syntheses of these four monocycles ultimately provided multigram quantities of each of the rings, supporting our efforts toward the completion of a convergent synthesis of brevetoxin A.

| S-EPMC2826130 | biostudies-literature

Biomimetic Approach to the Catalytic Enantioselective Synthesis of Flavonoids.

Project description:Herein is reported the direct asymmetric addition of phenol nucleophiles to benzopyrylium salts as a means to produce enantioenriched flavonoid-like compounds. This enantioselective C-C bond construction was achieved through a chiral anion phase-transfer strategy that mimics the proposed biosynthesis of this structurally diverse set of natural products. The utility of this methodology was demonstrated in enantioselective synthesis of a 2,8-dioxabicyclo[3.3.1]nonane and a 2,4-diarylbenzopyran.

| S-EPMC5149420 | biostudies-literature

A unified approach to the tedanolides: total synthesis of (+)-13-deoxytedanolide.

Project description:A unified approach for the construction of the potent marine antitumor agents (+)-tedanolide (1) and (+)-13-deoxytedanolide (2) is described. Highlights of the synthetic strategy include the development of a versatile bifunctional dithiane-vinyl iodide linchpin, the unorthodox use of the Evans-Tishchenko reaction, and a late-stage high-risk stereocontrolled introduction of the C(18,19) epoxide to achieve a total synthesis of (+)-13-deoxytedanolide (2).

| S-EPMC514431 | biostudies-other

Biomimetic approach to the catalytic enantioselective synthesis of tetracyclic isochroman.

Project description:Polyketide oligomers containing the structure of tetracyclic isochroman comprise a large class of natural products with diverse activity. However, a general and stereoselective method towards the rapid construction of this structure remains challenging due to the inherent instability and complex stereochemistry of polyketide. By mimicking the biosynthetic pathway of this structurally diverse set of natural products, we herein develop an asymmetric hetero-Diels-Alder reaction of in-situ generated isochromene and ortho-quinonemethide. A broad range of tetracyclic isochroman frameworks are prepared in good yields and excellent stereoinduction (up to 95% ee) from readily available α-propargyl benzyl alcohols and 2-(hydroxylmethyl) phenols under mild conditions. This direct enantioselective cascade reaction is achieved by a Au(I)/chiral Sc(III) bimetallic catalytic system. Experimental studies indicate that the key hetero-Diels-Alder reaction involves a stepwise pathway, and the steric hindrance between in-situ generated isochromene and t-Bu group of Sc(III)/N,N'-dioxide complex is responsible for the enantioselectivity in the hetero-Diels-Alder reaction step.

| S-EPMC8368254 | biostudies-literature

A Concise, Enantioselective Approach for the Synthesis of Yohimbine Alkaloids.

Project description:We report a concise, enantioselective synthesis of the yohimbine alkaloids (-)-rauwolscine and (-)-alloyohimbane. The key transformation involves a highly enantio- and diastereoselective NHC-catalyzed dimerization and an amidation/N-acyliminium ion cyclization sequence to furnish four of the five requisite rings and three of the five stereocenters in two operations. This route also provides efficient access to all four diastereomeric arrangements of the core stereotriad of the yohimbine alkaloids from a common intermediate. This platform approach in combination with the ability to access both enantiomers from the carbene-catalyzed reaction is a powerful strategy that can produce a wide range of complex alkaloids and related structures for future biomedical investigations.

| S-EPMC7185878 | biostudies-literature

A unified approach to polyene macrolides: synthesis of candidin and nystatin polyols.

Project description:Polyene macrolide antibiotics are naturally occurring antifungal agents. Members of this class include amphotericin B, which has been used widely to treat systemic fungal infections. A general synthetic strategy has been devised to prepare polyol chains associated with the polyene macrolides. Cyanohydrin acetonide alkylations were used to assemble the carbon skeleton, and a simple modification of the strategy allowed an advanced intermediate to be converted to either the candidin polyol or the nystatin polyol. The candidin polyol was further elaborated to a protected candidin aglycone. This strategy will be applicable to other members of the polyene macrolide natural products.

| S-EPMC514422 | biostudies-literature

On-surface synthesis of heptacene on Ag(001) from brominated and non-brominated tetrahydroheptacene precursors.

Project description:Achieving the Ag(001)-supported synthesis of heptacene from two related reactants reveals the effect of the presence of Br atoms on the reaction process. The properties of reactants, intermediates and end-products are further characterized by scanning tunneling microscopy and spectroscopy.

| S-EPMC6136266 | biostudies-literature

Enantioselective Synthesis of Carbo- and Heterocycles through a CuH-Catalyzed Hydroalkylation Approach.

Project description:The enantioselective, intramolecular hydroalkylation of halide-tethered styrenes has been achieved through a copper hydride-catalyzed process. This approach allowed for the synthesis of enantioenriched cyclobutanes, cyclopentanes, indanes, and six-membered N- and O-heterocycles. This protocol was applied to the synthesis of the commercial serotonin reuptake inhibitor (-)-paroxetine.

| S-EPMC4558994 | biostudies-literature

A unified approach for divergent synthesis of contiguous stereodiads employing a small boronyl group.

Project description:Acyclic contiguous stereocenters are frequently seen in biologically active natural and synthetic molecules. Although various synthetic methods have been reported, predictable and unified approaches to all possible stereoisomers are rare, particularly for those containing non-reactive hydrocarbon substituents. Herein, a ?-boronyl group is employed as a readily accessible handle for predictable ?-functionalization of enolates with either syn or anti selectivity depending on reaction conditions. Contiguous tertiary-tertiary and tertiary-quaternary stereocenters are thus accessed in generally good yields and diastereoselectivity. Based on experimental and computational studies, mechanism for syn selective alkylation is proposed, and Bpin (pinacolatoboronyl) behaves as a smaller group than most carbon-centered groups. The synthetic utility of this methodology is demonstrated by preparation of several key intermediates for bioactive molecules.

| S-EPMC7005891 | 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