Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Concise Approach to 1,4-Dioxygenated Xanthones via Novel Application of the Moore Rearrangement.

ABSTRACT: The rapid synthesis of 1,4-dioxygenated xanthones and related natural products employing the Moore rearrangement as a key transformation has been developed. The approach features an acetylide stitching step to unite a substituted squaric acid with a protected hydroxy benzaldehyde derivative to provide a key intermediate that undergoes facile Moore rearrangement to deliver a hydroxymethyl aryl quinone. Subsequent oxidation, hydroxy group deprotection and cyclization then affords highly functionalized xanthones. The utility of the approach was demonstrated by its application to a concise and efficient synthesis of the naturally-occurring xanthone 1. The structure of a natural product that had been named dulcisxanthone C was also corrected to that of the xanthone 1.

SUBMITTER: Nichols AL

PROVIDER: S-EPMC3432973 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Concise Approach to 1,4-Dioxygenated Xanthones via Novel Application of the Moore Rearrangement.

Nichols Alexander L AL Zhang Patricia P Martin Stephen F SF

Tetrahedron 20120901 37

The rapid synthesis of 1,4-dioxygenated xanthones and related natural products employing the Moore rearrangement as a key transformation has been developed. The approach features an acetylide stitching step to unite a substituted squaric acid with a protected hydroxy benzaldehyde derivative to provide a key intermediate that undergoes facile Moore rearrangement to deliver a hydroxymethyl aryl quinone. Subsequent oxidation, hydroxy group deprotection and cyclization then affords highly functional ...[more]

PMID: 22962501

Similar Datasets

General and expedient synthesis of 1,4-dioxygenated xanthones.

Project description:A facile entry to 1,4-dioxygenated xanthones having a variety of substitution patterns and substituents was developed that features a novel application of the Moore cyclization using substrates that were readily assembled in a highly convergent fashion by an acetylide stitching process. The practical utility of the methodology was demonstrated by an efficient synthesis of a naturally occurring xanthone and correction of the structure of dulcisxanthone C.

| S-EPMC3163007 | biostudies-literature

Approaches to polycyclic 1,4-dioxygenated xanthones. Application to total synthesis of the aglycone of IB-00208.

Project description:Hexacyclic xanthone natural products such as IB-00208 present a formidable challenge in organic synthesis. A new approach to polycyclic 1,4-dioxygenated xanthones from benzocyclobutenones has been developed and applied to the first total synthesis of the aglycone of IB-00208. The 22-step synthesis features an acetylide stitching process that joins an aryl aldehyde with an angularly fused benzocyclobutenone, which was prepared by a ring-closing metathesis reaction. The resulting acetylenic benzocyclobutenone diol underwent a Moore rearrangement to give an intermediate that was further elaborated to the aglycone of IB-00208 as a mixture of hydroquinone-quinone tautomers.

| S-EPMC4285456 | biostudies-literature

From Natural Xanthones to Synthetic C-1 Aminated 3,4-Dioxygenated Xanthones as Optimized Antifouling Agents.

Project description:Biofouling, which occurs when certain marine species attach and accumulate in artificial submerged structures, represents a serious economic and environmental issue worldwide. The discovery of new non-toxic and eco-friendly antifouling systems to control or prevent biofouling is, therefore, a practical and urgent need. In this work, the antifouling activity of a series of 24 xanthones, with chemical similarities to natural products, was exploited. Nine (1, 2, 4, 6, 8, 16, 19, 21, and 23) of the tested xanthones presented highly significant anti-settlement responses at 50 μM against the settlement of mussel Mytilus galloprovincialis larvae and low toxicity to this macrofouling species. Xanthones 21 and 23 emerged as the most effective larval settlement inhibitors (EC50 = 7.28 and 3.57 µM, respectively). Additionally, xanthone 23 exhibited a therapeutic ratio (LC50/EC50) > 15, as required by the US Navy program attesting its suitability as natural antifouling agents. From the nine tested xanthones, none of the compounds were found to significantly inhibit the growth of the marine biofilm-forming bacterial strains tested. Xanthones 4, 6, 8, 16, 19, 21, and 23 were found to be non-toxic to the marine non-target species Artemia salina (<10% mortality at 50 μM). Insights on the antifouling mode of action of the hit xanthones 21 and 23 suggest that these two compounds affected similar molecular targets and cellular processes in mussel larvae, including that related to mussel adhesion capacity. This work exposes for the first time the relevance of C-1 aminated xanthones with a 3,4-dioxygenated pattern of substitution as new non-toxic products to prevent marine biofouling.

| S-EPMC8618441 | biostudies-literature

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams.

Project description:Pyrrolidones are common heterocyclic fragments in various biologically active compounds. Here, a two-step radical-based approach to γ-lactams bearing three to four stereocenters starting from epoxides, N-allylic silylacetamides and TEMPO is reported. The sequence starts with a new tandem nucleophilic substitution/Brook rearrangement/single electron transfer-induced radical oxygenation furnishing orthogonally protected α,γ-dioxygenated N-allylamides with wide scope, mostly good yields, and partly good diastereo- and enantioselectivity for defined combinations of chiral epoxides and chiral amides. This represents a very rare example of an oxidative geminal C-C/C-O difunctionalization next to carbonyl groups. The resulting dioxygenated allylic amides are subsequently subjected to persistent radical effect-based 5-exo-trig radical cyclization reactions providing functionalized pyrrolidones in high yields as diastereomeric mixtures. They converge to 3,4-trans-γ-lactams by base-mediated equilibration, which can be easily further diversified. Stereochemical models for both reaction types were developed.

| S-EPMC7961876 | biostudies-literature

3,4-Dioxygenated xanthones as antifouling additives for marine coatings: in silico studies, seawater solubility, degradability, leaching, and antifouling performance.

Project description:Marine biofouling pollution is a process that impacts ecosystems and the global economy. On the other hand, traditional antifouling (AF) marine coatings release persistent and toxic biocides that accumulate in sediments and aquatic organisms. To understand the putative impact on marine ecosystems of recently described and patented AF xanthones (xanthones 1 and 2), able to inhibit mussel settlement without acting as biocides, several in silico environmental fate predictions (bioaccumulation, biodegradation, and soil absorption) were calculated in this work. Subsequently, a degradation assay using treated seawater at different temperatures and light exposures was conducted for a period of 2 months to calculate their half-life (DT50). Xanthone 2 was found to be non-persistent (DT50 < 60 days) at 50 μM, contrary to xanthone 1 (DT50 > 60 days). To evaluate the efficacy of both xanthones as AF agents, they were blended into four polymeric-based coating systems: polyurethane- and polydimethylsiloxane (PDMS)-based marine paints, as well as room-temperature-vulcanizing PDMS- and acrylic-based coatings. Despite their low water solubility, xanthones 1 and 2 demonstrated suitable leaching behaviors after 45 days. Overall, the generated xanthone-based coatings were able to decrease the attachment of the Mytilus galloprovincialis larvae after 40 h. This proof-of-concept and environmental impact evaluation will contribute to the search for truly environmental-friendly AF alternatives.

| S-EPMC10212850 | biostudies-literature

Synthesis of 1,3-diaminated stereotriads via rearrangement of 1,4-diazaspiro[2.2]pentanes.

Project description:The synthesis of 1,3-diaminated stereotriads via the bis-aziridination of allenes is reported. The reactive 1,4-diazaspiro[2.2]pentane intermediates undergo a mild Brønsted acid-promoted rearrangement to yield 1,3-diaminated ketones in good yields with excellent stereocontrol. Directed reduction of the ketone can be achieved to yield a C-N/C-O/C-N stereotriad in high dr. The ability to transfer the axial chirality of the substrates to the products allows for the facile preparation of enantioenriched stereotriads from allenes in two simple steps.

| S-EPMC4490830 | biostudies-literature

Si-based benzylic 1,4-rearrangement/cyclization reaction.

Project description:The trans-selective hydrosilylation of ynones (1) yields beta-silylated enones (2) that undergo a benzylic 1,4-rearrangement/cyclization reaction in the presence of base, yielding 2,5-dihydro-1,2-oxasiloles (3).

| S-EPMC2640427 | biostudies-literature

Synthesis of 1,4-dihydro-benzo[d][1,3]oxazin-2-ones from phthalides via an aminolysis-Hofmann rearrangement protocol.

Project description:A simple two-step procedure for the conversion of readily available phthalides to the corresponding benzoxazinones was developed. Initial ring-opening aminolysis to form a primary 2-hydroxymethylbenzamide, followed by reaction with bis(trifluoroacetoxy)iodobenzene (BTI) conveniently provided a variety of 4-substituted benzoxazinones.

| S-EPMC2194645 | biostudies-literature

Asymmetric retro-[1,4]-Brook rearrangement of 3-silyl allyloxysilanes <i>via</i> chirality transfer from silicon to carbon.

Project description:An asymmetric retro-[1,4]-Brook rearrangement of 3-silyl allyloxysilanes has been developed via Si-to-C chirality transfer. Mechanistic studies reveal that the silyl group migrates with retention of configuration. The stereochemical outcome of the newly formed stereogenic carbon center, which has remained a longstanding question, is also clarified, suggesting a diastereoselective Si to C chirality transfer without loss of enantiomeric excess.

| S-EPMC9070365 | biostudies-literature

Keith Arthur Moore

Project description: Not available

| S-EPMC555931 | biostudies-literature