Cyclopentenone Derivatives Research Articles

Acidic Ionic Liquid Catalyzed Liquefaction of Cellulose in Ethylene Glycol; Identification of a New Cellulose Derived Cyclopentenone Derivative

Cellulose can be liquefied in ethylene glycol at 180 °C, using 6.7 mol % 1-(1-alkylsulfonic)-3-methylimidazolium chloride ionic liquids as catalysts. The maximum liquefied product yields of 0.3436 and 0.3046 g/g of cellulose were achieved after 20 h at 180 °C using 1-(1-proylsulfonic)-3-methylimidazolium chloride and 1-(1-butylsulfonic)-3-methylimidazolium chloride as the catalysts. The liquefied oil produced from both ionic liquid catalysts had similar compositions. Unlike in previously reported mineral acid catalyzed cellulose liquefactions, the new catalysts give stable oils with well-defined compositions of only three compounds. The three compounds in the oil were identified as 2-hydroxyethyl levulinate, 2-hydroxyethyl levulinate ethylene ketal, and 2,3,6,7-tetrahydro-cyclopenta[1,4]dioxin-5-one using GC-MS, HRMS, and 1H, 13C, and 1H–1H COSY NMR spectroscopy. The third product 2,3,6,7-tetrahydro-cyclopenta[1,4]dioxin-5-one is a new C-6 carbohydrate derived cyclopentenone derivative, identified for the...

Synthesis and Antimicrobial Evaluation of Some Substituted-3-Aryl -2,3,4,5,6,7-hexahydro-1H-inden-1-one

Synthesis of new cyclopentenone derivatives by reacting 1-acetyl-1-cyclohexene with various aromatic and heteroaromatic aldehydes is reported. All the new cyclopentenone derivatives were characterized by 1 H, 13 C NMR, IR and mass spectral data, and were further screened for their antimicrobial activity. Most of the compounds showed comparable activities with standard drug ciprofloxacin and in particular, compounds 3d, 3f, 3g and 3j showed excellent activity against all the four bacterial strains.

ChemInform Abstract: A Convenient and Mild One Pot Synthesis of Cyclopentenone Derivatives.

Abstract Developed a convenient and mild one pot synthesis of cyclopentenone derivatives using 1-acetyl-1-cyclohexene and wide range of aldehydes. Aromatic and heterocyclic aldehydes with electron donating and withdrawing groups were conveniently converted to the corresponding cyclopentenone derivatives.

AlCl3-mediated aldol cyclocondensation of 1,6- and 1,7-diones to cyclopentene and cyclohexene derivatives.

Exactly 1/3 mol of AlCl3 is sufficient to cyclize 1 mol of 1,ω-dibenzoylbutane (or pentane) to a cyclopentenone (or hexenone) derivative in high yield at room temperature in 40 min to several hours. This condensation is driven by removing elements of water as HCl and Al(OH)3, and the product enones are exclusively unconjugated, unlike the base-catalyzed condensations providing thermodynamically more stable conjugated enones.

Three new cyclopentenone derivatives from Actinoalloteichus nanshanensis NEAU 119

Three new cyclopentenone derivatives (1–3) were isolated from the rare actinomycete Actinoalloteichus nanshanensis NEAU 119. Their structures were elucidated by extensive spectroscopic analysis. Compound 1 showed moderate cytotoxic activity against human lung adenocarcinoma cell line A549, human leukemia cell line K562, and human renal carcinoma cell line ACHN with an IC50 of 14.67, 11.87, and 23.36 μg ml− 1, respectively.

Catalytic Enantioselective Nazarov Cyclization: Construction of Vicinal All‐Carbon‐Atom Quaternary Stereocenters

AbstractThe diastereoselective asymmetric synthesis of vicinal all‐carbon‐atom quaternary stereocenters is a challenging problem in organic synthesis for which only few solutions have been described. A catalytic asymmetric Nazarov cyclization of fully substituted dienones that provides cyclopentenone derivatives with vicinal quaternary stereocenters in high optical purity and as single diastereoisomers is now reported.

Catalytic Enantioselective Nazarov Cyclization: Construction of Vicinal All‐Carbon‐Atom Quaternary Stereocenters

The diastereoselective asymmetric synthesis of vicinal all-carbon-atom quaternary stereocenters is a challenging problem in organic synthesis for which only few solutions have been described. A catalytic asymmetric Nazarov cyclization of fully substituted dienones that provides cyclopentenone derivatives with vicinal quaternary stereocenters in high optical purity and as single diastereoisomers is now reported.

Natural products from mangrove actinomycetes.

Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery.

ChemInform Abstract: Suberosanones A—C, New Metabolites Possessing Cyclopentenone System from the South China Sea Gorgonian Coral Subergorgia suberosa.

AbstractThe bicyclic latones, suberosanones A (I) and B (II), and the tricyclic cyclopentenone derivative, suberosanone C (III) show neither antifouling activity against Balanus amphitrite larvae settlement nor antibacterial activity against a panel of bacterial strains.

Highly Diastereoselective Synthesis of Cyclopentenones via a One-Pot Gold Catalysis, Nazarov Cyclization and Alkylation Cascade

Starting from readily available propargylic carboxylates, three sequential transformations [gold-catalyzed tandem reaction, scandium(III) trifluoromethanesulfonate catalyzed Nazarov cyclization, alkylation reaction] in a one-pot process led to the formation of cyclopentenone derivatives in excellent diastereoselectivities and moderate to good overall yields.

A convenient and mild one pot synthesis of cyclopentenone derivatives

Developed a convenient and mild one pot synthesis of cyclopentenone derivatives using 1-acetyl-1-cyclohexene and wide range of aldehydes. Aromatic and heterocyclic aldehydes with electron donating and withdrawing groups were conveniently converted to the corresponding cyclopentenone derivatives.

Peter Ludwig Pauson (1925–2013)

Peter Ludwig Pauson (1925–2013)

Suberosanones A – C, New Metabolites Possessing Cyclopentenone System from the South China Sea Gorgonian Coral Subergorgia suberosa

AbstractTwo unusual novel bicyclic lactones, suberosanones A and B (1 and 2, resp.), characterized by the co‐occurrence of cyclopentenone and butanolide rings within the same molecule, along with one tricyclic cyclopentenone derivative, suberosanone C (3), were isolated from the South China Sea gorgonian coral Subergorgia suberosa. Their structures were unambiguously established by detailed spectroscopic analyses (NMR, IR, and HR‐MS). The absolute configurations of 1 and 2 were determined by quantum‐chemical calculations using the time‐dependent density‐functional theory (TDDFT) method. All compounds showed neither antifouling activity against Balanus amphitrite larvae settlement nor antibacterial activity against a panel of bacterial strains at concentrations up to 25 μg/ml.

ChemInform Abstract: Catalyzed Addition of Acid Chlorides to Alkynes by Unmodified Nano‐Powder Magnetite: Synthesis of Chlorovinyl Ketones, Furans, and Related Cyclopentenone Derivatives.

Abstract Inexpensive and commercially available nano-powder magnetite is an excellent catalyst for the addition of acid chlorides to internal and terminal alkynes, yielding the corresponding chlorovinyl ketones in good yields. The process has been applied to the synthesis of 5-chloro-4-arylcyclopent-2-enones, 3-aryl-1H-cyclopenta[a]naphthalen-1-ones, and (E)-3-alkylidene-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-ones, just by changing the nature of the starting acid chloride or the alkyne. All tested processes elapse with an acceptable or excellent regio- and stereo-selectivity. Moreover, the use of the iridium impregnated on magnetite catalyst permits the integration of the chloroacylation process with a second dehydrochlorination–annulation process to yield, in one-pot, 1-aryl-2,4-dialkylfurans in good yields, independently of the nature of the starting reagents, and including the heteroaromatic ones.

Mild conversion of propargylic alcohols to α,β-unsaturated enones in ionic liquids (ILs); a new ‘metal free’ life for the Rupe rearrangement

A mild and selective transition metal free protocol for the conversion of propargylic alcohols to cyclic and acyclic α,β-unsaturated enones via the Rupe rearrangement is reported. The method utilizes the Brønsted acidic ionic liquid [BMIM-SO3H][OTf] as catalyst and [BMIM][PF6] as solvent and offers the potential for recycling and reuse of the IL solvent. The feasibility to synthesize bicyclic fused cyclopentenone derivatives via a Rupe→Aldol→Nazarov sequence utilizing this protocol has also been demonstrated.

Acacia ferruginea Inhibits Tumor Progression by Regulating Inflammatory Mediators-(TNF-α, iNOS, COX-2, IL-1β, IL-6, IFN-γ, IL-2, GM-CSF) and Pro-Angiogenic Growth Factor-VEGF

The aim of the present investigation was to evaluate the effect of A ferruginea extract on Dalton's lymphoma ascites (DLA) induced tumours in BALB/c mice. Experimental animals received A ferruginea extract (10 mg/ kg.b.wt) intraperitoneally for 14 consecutive days after DLA tumor challenge. Treatment with extract significantly increased the life span, total white blood cell (WBC) count and haemoglobin (Hb) content and decreased the level of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (γ-GT) and nitric oxide (NO) in DLA bearing ascites tumor models. In addition, administration of extract significantly decreased the tumour volume and body weight in a DLA bearing solid tumor model. The levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and granulocyte monocyte-colony stimulating factor (GM-CSF), as well as pro-angiogenic growth factors such as vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) were elevated in solid tumour controls, but significantly reduced by A ferruginea administration. On the other hand, the extract stimulated the production of interleukin-2 (IL-2) and interferon-gamma (IFN-γ) in animals with DLA induced solid tumours. Increase in CD4+ T-cell population suggested strong immunostimulant activity for this extract. GC/MS and LC/MS analysis showed quinone, quinoline, imidazolidine, pyrrolidine, cyclopentenone, thiazole, pyrazole, catechin and coumarin derivatives as major compounds present in the A ferruginea methanolic extract. Thus, the outcome of the present study suggests that A ferruginea extract has immunomodulatory and tumor inhibitory activities and has the potential to be developed as a natural anticancer agent.

Catalyzed addition of acid chlorides to alkynes by unmodified nano-powder magnetite: synthesis of chlorovinyl ketones, furans, and related cyclopentenone derivatives

Inexpensive and commercially available nano-powder magnetite is an excellent catalyst for the addition of acid chlorides to internal and terminal alkynes, yielding the corresponding chlorovinyl ketones in good yields. The process has been applied to the synthesis of 5-chloro-4-arylcyclopent-2-enones, 3-aryl-1H-cyclopenta[a]naphthalen-1-ones, and (E)-3-alkylidene-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-ones, just by changing the nature of the starting acid chloride or the alkyne. All tested processes elapse with an acceptable or excellent regio- and stereo-selectivity. Moreover, the use of the iridium impregnated on magnetite catalyst permits the integration of the chloroacylation process with a second dehydrochlorination–annulation process to yield, in one-pot, 1-aryl-2,4-dialkylfurans in good yields, independently of the nature of the starting reagents, and including the heteroaromatic ones.

Novel cyclopentenone derivatives produced by a rare actinobacterial strain Actinoalloteichus nanshanensis sp. nov. NEAU 119

Four novel cyclopentenone derivatives (1–4), characterising a cyclopentenone ring conjugated with a 1,8-dioxadecalin, were isolated from rare actinobacterial strain Actinoalloteichus nanshanensis sp. nov. NEAU 119. The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis. Bioassays indicated that compounds 1–4 showed low cytotoxicities against human leukaemia cell line K562 and human renal carcinoma cell line ACHN. To the best of our knowledge, this is the first example of isolation of C11 cyclopentenones from actinomycetes.

(−)-8-Amino menthol-derived perhydrobenzoxazines as chiral templates and masked aldehydes in the diastereoselective intermolecular Pauson–Khand reaction

Perhydro-1,3-benzoxazines derived from (−)-8-amino menthol behave as masked aldehydes and chiral templates in diastereoselective intramolecular Pauson–Khand reactions with norbornene and norbornadiene. The regioselectivity is excellent for unsubstituted or methyl-substituted acetylenes and moderate with phenyl-substituted alkynes. The stereoselection is very poor or moderate depending also on the substitution pattern of both the triple bond and the perhydrobenzoxazine nucleus. The hydrolysis of the cycloadducts leads to 2- or 3-formyl–cyclopentenone derivatives.

A novel synthesis of fluorine-containing cyclopentenones via Pauson–Khand reaction

Intermolecular Pauson–Khand reaction of fluoroalkylated alkynes with 2-norbornene or 2,5-norbornadiene at the reflux temperature of dichloroethane proceeded smoothly to give the corresponding cyclopentenone derivatives in high yields as a mixture of regioisomers. On the other hand, intramolecular Pauson–Khand reaction of fluorine-containing 1,6-enyne proceeded in the presence of NMO or TMANO to give the bicyclic adducts in good yields. Additionally, allyl CF3-propargyl ether also underwent a smooth Pauson–Khand reaction in the presence of amine oxide, the corresponding bicyclic compounds being obtained in a highly diastereoselective manner.