Polyoxygenated Cyclohexenes Research Articles

Polyoxygenated Cyclohexene Derivatives fromUvaria rufa

Four new polyoxygenated cyclohexene derivatives, uvarirufone A (1) and uvarirufols A–C (2–4), along with ten related known compounds, were isolated from the EtOH extract of the aerial parts of Uvaria rufaBl. Their structures and absolute configurations were determined by in-depth spectroscopic and spectrometric methods in combination with molecular modeling.

Cytotoxic C-benzylated chalcone and other constituents ofEllipeiopsis cherrevensis

A new natural C-benzylated chalcone, 2',4'-dihydroxy-3'-(2-hydroxybenzyl)-6'-methoxychalcone (2), along with two other flavonoids, tiliroside and kaempferol 3-O-rutinoside, and an oxoaporphine alkaloid, lanuginosine were isolated from the aerial parts of Ellipeiopsis cherrevensis (Annonaceae). Two known polyoxygenated cyclohexene derivatives, ferrudiol and zeylenol, and a new analog, ellipeiopsol D, were also isolated. The chalcone 2 exhibited cytotoxic activity against human small-cell lung-cancer (NCI-H187), epidermoid carcinoma (KB) and breast cancer (BC) cell lines with IC50 values of 1.40, 5.31 and 13.92 microg/mL, respectively. This compound also showed antimalarial activity against Plasmodium falciparum with an IC50 value of 7.1 microg/mL as well as antimicrobacterial activity against Mycobacterium tuberculosis with a MIC of 25 mg/mL.

New Polyoxygenated Cyclohexenes from Uvaria kweichowensis and Their Antitumour Activities

Two new polyoxygenated cyclohexenes, kweichowenol A and B, were isolated from the leaves of Uvaria kweichowensis, and their structures were established on the basis of their spectral data. The two new compounds showed some antitumour activity by MTT assay.

Is potential coordination of alkali metal ions to stereodefined polyoxygenated cyclohexanes an adequate driving force for fostering the adoption of axial conformers?

Inositol orthoesters have been developed as precursors to stereodefined hexakis polyoxygenated cyclohexanes. The objective of the study was to determine if all- trans systems could be coaxed by alkali metal ions into adopting the all- axial coordinative features. This high level coordination cannot be matched by epimers whose only option is to experience monocomplexation. Only very low levels of coordination were exhibited in solution by the ligands in question. Electrospray ionization mass spectrometry was also used to evaluate the metal complexation properties of the inositol ligands based on competition experiments involving each ligand and one or more metals.

Polyoxygenated Cyclohexenes from the Chinese Tree,Uvaria Purpurea

Four new polyoxygenated cyclohexenes, 2-O-acetyl-6-O-methylzeylenol (2), 2-O-benzoyl-3-O-debenzoylzeylenone (5), 3-O-debenzoylzeylenone (6) and 3-O-debenzoylgrandiflorone (8), were isolated from the leaves of Uvaria purpurea. 2-O-acetyl-6-O-benzoylzeylenol (3) was also isolated for the first time as a natural product. Compounds 5-7 each showed inhibitory activity against the root growth of Lactuca sativa. Their structures were established by spectroscopic and chemical methods.

Polyoxygenated cyclohexene derivatives from Ellipeiopsis cherrevensis

Aerial parts of Ellipeiopsis cherrevensis contained the polyoxygenated cyclohexenes zeylenol, ferrudiol and three analogs, ellipeiopsols A, B and C. The C-1 stereochemistry of ferrudiol has been revised.

Four polyoxygenated cyclohexenes from the Chinese tree, Uvaria purpurea.

Two novel polyoxygenated cyclohexenes, 6-methoxyzeylenol (3) and 2-acetoxyzeylenone (4), together with two known compounds, zeylenol (1) and zeylenone (2), were isolated from the heartwood of the Chinese tree, Uvaria purpurea. Zeylenol (1) and zeylenone (2) both showed inhibitory activity toward the root growth of Lactuca sativa. Their structures were established by spectroscopic and chemical methods.

The first synthesis of (-)-asperpentyn and efficient syntheses of (+)-harveynone, (+)-epiepoformin and (-)-theobroxide.

A generally applicable strategy for the synthesis of a range of polyoxygenated cyclohexane natural products has been developed. The enantioselective syntheses of (-)-theobroxide, a polyoxygenated cyclohexane natural compound with potent growth inducing properties in potato microtubers has been achieved via a 1,2 O-silyl migration between trans-hydroxyl groups and a remote hydroxyl directed epoxidation of an enone derived from quinic acid. A thus derived alpha-iodoenone was subjected to Stille coupling with tetramethylstannane to afford the first title compound. A similar strategy enabled a route to the complete asymmetric synthesis of the acetylenic phytotoxin (+)-harveynone. By selective reduction of (-)-theobroxide, (+)-epiepoformin was also prepared in enantiopure form and similarly, stereoselective reduction of (+)-harveynone completed the first enantioselective synthesis of (-)-asperpentyn, another natural compound with antimicrobial activity.

Recent works on anti-tumor constituent from Annonaceae plants in China

Abstract

Synthetic research on cyclitols using C 6-chiron, 6-(benzyloxy)-3-cyclohexen-1-ol: A concise and highly diastereoselective synthesis of (−)- gala-quercitol

Transformation of a C 6-chiron, 6-(benzyloxy)-3-cyclohexen-1-ol into polyoxygenated cyclohexanes involving a stereodivergent epoxide rearrangement was investigated. An asymmetric synthesis of (−)- gala-quercitol was accomplished via sequential highly diastereoselective epoxidation, base-promoted epoxide rearrangement, and dihydroxylation.

New Polyoxygenated Cyclohexenes from Uvaria Calamistrata

Five new polyoxygenated cyclohexenes, named uvacalol A (1), B (2), C (3), D (4) and E (5) were isolated from the roots of Uvaria calamistrata. On the basis of spectral analysis and chemical derivatization, including the preparation of Mosher esters, the structures of compound 1–5 were established as (2R,3S,4R,5S)-2-acetoxyl-5-ethoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-3,4-diol-3-benzoate, (2R,3S,4R,5S)-2-acetoxyl-5-ethoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-3,4-diol-4-benzoate, (2R,3S,4R,5S)-5-ethoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-2,3,4-triol-3-benzoate, (2R,3S,4R,5S)-3-methoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-2,3,5-triol and (2R,3S,4R,5S)-2-acetoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-3,4,5-triol-5-benzoate, respectively.

ChemInform Abstract: Norbornyl Route to Polyoxygenated Cyclohexanes. An Approach to Pancratistatin and Narciclasine Alkaloids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Norbornyl Route to Polyoxygenated Cyclohexanes. A Facile Entry into Carbasugars and Shikimic Acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Norbornyl route to polyoxygenated cyclohexanes. A facile entry into carbasugars and shikimic acid

A short, stereoselective entry to carbasugars and shikimic acid from a readily available 7-norbornenone is reported.

Norbornyl route to polyoxygenated cyclohexanes. An approach to pancratistatin and narciclasine alkaloids

A stereoselective approach to densely functionalized cyclohexanoids from 7-norbornenone is delineated. Construction of the phenanthridone core present in pancratistatin has been accomplished through this protocol. Graphic

Polyoxygenated cyclohexenes from Uvaria grandiflora

Three new polyoxygenated cyclohexenes, named uvarigranol G-I, along with two known compounds, 1-epizeylenol and zeylenyl 2,6-diacetate, were isolated from the roots of Uvaria grandiflora. Based on spectral analyses and chemical derivitization, their absolute stereostructures were established.

Tonkinenin a. A new polyoxygenated cyclohexane derivative from Uvaria tonkinensis

The ethanolic extract of the seeds of Uvaria tonkinensis (Annonaceae), collected on Hainan Island, have led to the isolation of a new polyoxygenated cyclohexane derivative tonkinenin A [ 1]. The structure of 1 was deduced from spectroscopic characteristics and the absolute stereochemistry assigned by the O-methylmandelate ester method.

Reactions of diphenylketene and methylphenylketene with some cis-cyclohexa-3,5-diene-1,2-diol derivatives

The reaction of the dienes 1–5 with diphenylketene to give the [2 + 2]-adducts 6–10 and the [4 + 2]-adducts 11–15, respectively, has been found to occur by an ionic mechanism involving the zwitterion 16. The reactions of the dienes 2 and 3 with methylphenylketene (and also cyclohexa-1,3-diene with diphenylketene) proceed in a similar fashion. The enol ether 13 was converted into the polyoxygenated cyclohexane derivatives 33, 35 and 38.

Two polyoxygenated cyclohexenes from Uvaria grandiflora

Two new polyoxygenated cyclohexenes with a rare ethoxy group, named uvarigranols C and D, were isolated from the roots of Uvaria grandiflora. Their structures were established by spectroscopic and chemical methods.

ChemInform Abstract: Tandem Pericyclic Reactions. The First X‐Ray Structure and an Initial Pyrone‐Olefin Adduct and an Easy, Stereocontrolled, Entry into Polyoxygenated Cyclohexanes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.