2006-14-6

With the increase of fungal infection and drug resistance, it is becoming an urgent task to discover the highly effective antifungal drugs. In the study, we selected the key ergosterol bio-synthetic enzymes (Squalene epoxidase, SE; 14 α-demethylase, CYP51) as dual-target receptors to guide the construction of novel antifungal compounds, which could achieve the purpose of improving drug efficacy and reducing drug-resistance. Three different series of amide naphthyl compounds were generated through the method of skeleton growth, and their corresponding target products were synthesized. Most of compounds displayed the obvious biological activity against different Candida spp. and Aspergillus fumigatus. Among of them, target compounds 14a-2 and 20b-2 not only possessed the excellent broad-spectrum anti-fungal activity (MIC50, 0.125–2 μg/mL), but also maintained the anti-drug-resistant fungal activity (MIC50, 1–4 μg/mL). Preliminary mechanism study revealed the compounds (14a-2, 20b-2) could block the bio-synthetic pathway of ergosterol by inhibiting the dual-target (SE/CYP51) activity, and this finally caused the cleavage and death of fungal cells. In addition, we also discovered that compounds 14a-2 and 20b-2 with low toxic and side effects could exert the excellent therapeutic effect in mice model of fungal infection, which was worthy for further in-depth study.

Partial agonist activity at the dopamine D2 receptor (D2R) is the primary pharmacological feature of the third-generation antipsychotics─aripiprazole, brexpiprazole, and cariprazine. However, all these drugs share a common phenyl-piperazine moiety as the primary pharmacophore. In this study, we designed and synthesized a series of novel compounds based on the 2-phenylcyclopropylmethylamine (PCPMA) scaffold and studied their pharmacological activity at the D2R. A number of potent D2R partial agonists were identified through binding affinity screening and functional activity profiling in both G protein and β-arrestin assays. The structure-functional activity relationship results showed that the spacer group is crucial for fine-tuning the intrinsic activity of these compounds. Compounds (+)-14j and (+)-14l showed good pharmacokinetic properties and an unexpected selectivity against the serotonin 2A (5-HT2A) receptor. Preliminary suppressive effects in a mouse hyperlocomotion model proved that these PCPMA-derived D2R partial agonists are effective as potential novel antipsychotics.

Two new series of conjugated arylethenyl-1,3,4-oxadiazolyl-1,2,4-oxadiazoles were obtained and spectroscopically characterized in terms of UV-Vis absorption, fluorescence and interaction with CT-DNA and Human Serum Albumin (HSA) biomolecules. Phenyl- and 1-naphthyl-bearing examples were analysed, and the spectroscopic properties of its substitution series were compared, showing extensive conjugation in all compounds and absorption differences due to both the aryl-ethenyl subunit and substituted phenyl/phenylene at the 1,2,4-oxadiazole side. Strong binding interactions of the obtained compounds with CT-DNA and moderate HSA-association capability were observed spectroscopically, and further docking studies were performed. This journal is

A practical and general iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabling aldehyde C-H methylation for the synthesis of methyl ketones has been developed. This mild, operationally simple method uses ambient air as the sole oxidant and tolerates sensitive functional groups for the late-stage functionalization of complex natural-product-derived and polyfunctionalized molecules.

A Hf(IV) metal-organic framework (MOF) with di-amino functionalized linker was obtained as a crystalline solid with UiO-67 topology under solvothermal reaction conditions. The guest free form of Hf(IV) MOF (1′) was efficiently employed as a heterogeneous catalyst to synthesize cinnamic acid derivatives via Knoevenagel-Doebner reaction for the first time. The catalyst (1′) was efficiently active to directly achieve cinnamic acid from benzaldehyde and malonic acid. The solid retained its activity up to 6th cycle with no decay in its activity. The noticeable advantages of the catalyst are its milder reaction conditions, high yield, high stability, recyclable nature towards catalysis and wide substrate scope as well as shape-selective behaviour. The possible mechanism of the reaction was also studied thoroughly with suitable control experiments.

Amino acid conjugates are combinations of one or more compounds, at least one of them active in terms of biological, pharmacological or physical. In this work, some novel amino acid conjugates, four different aldehydes (Pyrene, Naphthalene, Phenanthrene and Phenyl benzyl) have been chosen and from these initial materials four different amino acid conjugates were synthesized. The compounds from initial steps to final steps have been characterized by 1H and 13C APT NMR spectroscopy. The dielectric measurements were done by QuadTech 7600 LRC impedance analyzer. The dielectric constant (ε′) dielectric loss (ε’’) and ac conductivity (σ) values of amino acid conjugates in the frequency of 1 kHz and at 25 °C. The results show that the increase in conjugation affect the dielectric constant and conductivity.

Herein, we present the first example of synthesis of 3,4-dihydropyran-2-ones from cinnamic thioesters via a stereoselective phase-transfer-catalyzed domino Michael-cyclization reaction with acetylacetone. The reaction proceeded under the catalysis of Cinchona-derived quaternary ammonium phenoxide that, in combination with inorganic bases, provided 3,4-dihydropyran-2-ones in yields of up to 93% and enantioselectivities of up to 88% enantiomeric excess.

Background: Cinnamic acid is a key intermediate in shikimate and phenylpropanoid pathways. It is found both in free form, and especially in the form of esters in various essential oils, resins and balsams which are very important intermediates in the biosynthetic pathway of several natural products. The cinnamic derivatives play a vital role in the formation of commercially important intermediate molecules which are necessary for the production of different bioactive compounds and drugs. Different substitutions on basic moiety lead to various biological activities. Furthermore, combination of appropriate pharmacophore groups with cinnamic acid derivatives were developed to give hybrids in order to find out promising drug candidates as inhibitors of multiple biological targets associated with inflammation. We found interesting to continue our efforts to design and synthesise three series of novel cinnamic acid-based hybrids: a) nitrooxy esters of cinnamic acid, b) ethers and c) amides of cinnamic acids with arginine, as pleiotropic candidates against multiple targets of inflammation Methods: The synthesis of cinnamic was established by a Knoevenagel-Doebner condensation of the suitable aldehyde either with malonic acid in the presence of pyridine and piperidine, or with phenylacetic acid in the precence of triethylamine in acetic anhydride. The synthesis of the corresponding esters was conducted in two steps. The ethers were synthesized in low yields, with 1,2 – dibromoethane in dry acetone, in the presence of K2CO3, to give oily products. The corresponding cinnamic amides were synthesised in a single step. The synthesised hybrids were tested as lipoxygenase (LOX) and cyclooxygenase (COX) inhibitors in vitro. In silico docking was applied to all the novel derivatives. Several molecular properties of the hybrids were calculated in order to evaluate their drug likeness. Results: A number of esters, ethers and amides of selected cinnamic acids, either phenyl substituted or not, has been synthesised and subjected to modelling studies. The compounds were studied in vitro/in vivo for their inhibitory activities on cox and lox, and as antioxidants. Log P values of all the title compounds except of 3a (5.38) were found to be less than 5 and are in agreement to Lipinski’s rule of five, suggesting satisfactory permeability across cell membrane. The molecular modelling study seems to be in accordance with the experimental results for LOX and COX-2. The result of antioxidant activity for amide 3b supports the anti-lox activity. Compound 5d presents the higher in vivo anti-inflammatory. Conclusion: According to the experimental findings compounds 3b and 5d can be used as lead compounds for the design of new molecules to target inflammation.

Ergosterol as the core component of fungal cell membrane plays a key role in maintaining cell morphology and permeability. The squalenee epoxidase (SE) and 14-demethylase (CYP51) are the important rate-limiting enzymes for ergosterol synthesis. In the study, these active fragments, which is derived from the structural groups of the common antifungal agents, were docked into the active sites of dual targets (SE, CYP51), respectively. Some of active fragments with the matching MCSS_Score values were selected and connected to construct three different series of novel arylalkene-amide derivatives as dual-target (SE, CYP51) antifungal inhibitors. Subsequently, these compounds were further synthesized, and their bioactivity was evaluated. Most of compounds showed a certain degree of antifungal activity in vitro. It was worth noting that the target compounds 17a and 25a with excellent antifungal activity (0.125–4 μg/mL) can inhibit the fluconazole-resistant Candida Strain 17#, CaR, 632, and 901 in the range of MIC values (4–8 μg/mL). Furthermore, their molecular mechanism, structural stability and low toxicity were further confirmed. The molecular docking and ADMET properties were predicted to guide the subsequent optimization of target compounds.

Compounds, methods of synthesis, and methods of cancer treatment by arylidene-1,3-dioxane-4,6-diones. A Meldrum's acid-based chemistry and hybrid solid-liquid method. The method includes protection of ketone and aldehyde components and simultaneous immobilization on the solid phase, introduction of substituents, grafts and derivatives compatible with the protection, detachment and restoration of active carbonyl reactivity, reaction of ketone library with malonate, reacting of the products with the aldehyde library in liquid phase and separation of the products by preparative HPLC.

Cinnamic acid and its derivatives are known for anti-tubercular activity. The present study reports the synthesis of cinnamic acid derivatives via bioisosteric replacement of terminal carboxylic acid with “oxadiazole”. A series of cinnamic acid derivatives (styryl oxadiazoles) were designed and synthesized in good yields by reaction of substituted cinnamic acids (2, 15a-15s) with amidoximes. The synthesized styryl oxadiazoles were evaluated in vitro for anti-tubercular activity against Mycobacterium tuberculosis (Mtb) H37Ra strain. The structure-activity relationship (SAR) study has identified several compounds with mixed anti-tubercular profiles. The compound 32 displayed potent anti-tubercular activity (IC50 = 0.045 μg/mL). Molecular docking studies on mycobacterial enoyl-ACP reductase enzyme corroborated well with the experimental findings providing a platform for structure based hit-to-lead development.

The development of novel neuroprotection agents is of great significance for the treatment of ischemic stroke. In this study, a series of compounds comprising 2,2-dimethylbenzopyran groups and cinnamic acid groups have been synthesized. Preferential combination principles and bioisostere that improved the neuroprotective effect of the compounds were identified for this series via biological activity assay in vitro. Meanwhile, a functional reversal group of the acrylamide amide resulted in the most active compounds. Among them, BN-07 significantly improved the morphology of neurons and obviously increased cell survival rate of primary neurons induced by oxygen glucose deprivation (OGD), superior to clinically used anti-ischemic stroke drug edaravone (Eda). Overall, our findings may provide an alternative strategy for the design of novel anti-ischemic stroke agents with more potency than Eda.

Concise total syntheses of the natural phytoalexins 2-hydroxy-8-(4-hydroxyphenyl)phenalen-1-one (1), 2-hydroxy-8-(3,4-dihydroxyphenyl)phenalen-1-one (2), and hydroxyanigorufone (4), together with regioisomer 3 are accomplished in 11 or 12 steps. The synthetic strategy features a Friedel-Crafts acylation to construct the 1H-phenalen-1-one tricyclic core followed by a Suzuki cross-coupling to obtain the target compounds.

The invention belongs to the technical field of medicines, and discloses a 2,2-dimethylbenzopyran derivative and a preparation method and use of the 2,2-dimethylbenzopyran derivative. The derivative and pharmaceutically acceptable salt of the derivative have the structural formulae shown in the description, wherein Ar, Ar, X, Y and R1 are as described in the claims and the description. The preparation methods of the derivative and the pharmaceutically acceptable salt of the derivative comprise the following steps: the formula (I) is obtained by mainly taking acetaminophen as a raw material, and subjected to the reactions of Williamson ether formation, cyclization, hydrolysis, amide formation and the like; the formula II is obtained by mainly taking p-hydroxybenzaldehyde as a raw material, and subjected to the reactions of the Williamson ether formation, cyclization, Knoevenagel condensation, amide formation and the like. The derivative and the pharmaceutically acceptable salt ofthe derivative disclosed by the invention can be used for preparing neuroprotective agents and have better neuroprotective effects on ischemic stroke.

The first workable application of β-nitrostyrenes and CBr4 as coupling partners for a highly stereoselective synthesis of (E)-cinnamic acids under visible light photoredox catalysis is reported. The reaction involves a radical denitrative tribromomethylation/hydrolysis cascade to afford (E)-cinnamic acids in excellent yields at room temperature in a one-pot procedure. Moreover, the implementation of visible light as a clean and inexpensive energy source and CBr4 as the latent source of carboxylic groups makes the protocol reconcilable with the present day scenario of organic synthesis.

Maleic anhydride was explored as a substitute for acrylic acid to synthesize cinnamic acids from aryl halides under heterogeneous palladium catalyzed conditions. The combined role of surface and impregnated catalyst together performed an upright engineering to hold in situ generated molecules on the surface and subsequently facilitate their interaction for the desired product synthesis. Overall, a surface mediated approach for cinnamic acid synthesis from maleic anhydride following a major unexplored pathway through catalyst promoted decarboxylation was critically investigated.

Cinnamyl- and thiazole-based compounds have been shown to exhibit diverse medicinal properties and a series of twelve (E)-2-styrylthiazole and (E)-2-[(naphthalen-1-yl)vinyl]thiazole derivatives, which are conjugates of both systems and which satisfy the "Lipinski rule of 5", have been synthesised and subjected to in vitro biological screening. While insignificant inhibition (60-98% viability at 10 μM) of HeLa (cervical cancer) cells was noted, all five of the (E)-2-[naphthalen-1- yl)vinyl]thiazole derivatives proved remarkably active against SH-SY5Y (neuroblastoma) cells with IC50 values ranging from 2.09 to 8.64 μM. Two of the seven (E)-2-styrylthiazoles were found to be moderately active (with IC50 values of 10.8 and 11.7 mM), whereas the remaining five analogues exhibit significant proliferation of SH-SY5Y cells (with IC50 values of 180-1000 mM). The results warrant further studies on the effects of styrylthiazoles on the differentiation and extension of SH-SY5Y cells in order to assess their activity in neurological degenerative diseases.

Cinnamyl- and thiazole-based compounds have been shown to exhibit diverse medicinal properties and a series of twelve (E)-2-styrylthiazole and (E)-2-[(naphthalen-1-yl)vinyl]thiazole derivatives, which are conjugates of both systems and which satisfy the “Lipinski rule of 5”, have been synthesised and subjected to in vitro biological screening. While insignificant inhibition (60-98% viability at 10 μM) of HeLa (cervical cancer) cells was noted, all five of the (E)-2-[naphthalen-1-yl)vinyl]thiazole derivatives proved remarkably active against SH-SY5Y (neuroblastoma) cells with IC50 values ranging from 2.09 to 8.64 μM. Two of the seven (E)-2-styrylthiazoles were found to be moderately active (with IC50 values of 10.8 and 11.7 mM), whereas the remaining five analogues exhibit significant proliferation of SH-SY5Y cells (with IC50 values of 180-1000 mM). The results warrant further studies on the effects of styrylthiazoles on the differentiation and extension of SH-SY5Y cells in order to assess their activity in neurological degenerative diseases.

Oxidative Se-catalyzed C(sp3)-H bond acyloxylation has been used to construct a diverse array of isobenzofuranones from simple ortho-allyl benzoic acid derivatives. The synthetic procedure employs mild reaction conditions and gives high chemoselectivity enabled by an inexpensive organodiselane catalyst. The presented approach offers a new synthetic pathway toward the core structures of phthalide natural products.

A domino Knoevenagel-decarboxylation-alkene difunctionalization sequence has been developed for the conversion of benzaldehydes into β-ketophosphonates, catalyzed by a cooperative Cu/Fe system, whereby CP and CO bonds are formed simultaneously in a one-pot reaction. The reaction proceeds in good yields and with a broad substrate scope and environmentally benign conditions.

N-(Arylcyclopropyl)acetamides and N-(arylvinyl)acetamides or methyl ureas have been prepared as constrained analogues of melatonin. The affinity of these new compounds for chicken brain melatonin receptors and recombinant human MT1 and MT2 receptors was evaluated using 2-[ 125I]-iodomelatonin as radioligand. Strict ethylenic or cyclopropyl analogues of the commercialized agonist agomelatine (Valdoxan) were equipotent to agomelatine in binding bioassays. However, the ethylenic analogue was more effective than the cyclopropyl one in the melanophore aggregation bioassay, but was still less potent than the disubstituted 2,7-dimethoxy- naphtalenic compounds.

α,β-Unsaturated acids are very useful and versatile reagents in organic synthesis. A novel, practical, and convenient catalytic protocol comprising FeCl3·6H2O (0.5 mol %) and H 2O (1 equiv) in CH3NO2 is described for the rapid synthesis of α,β-unsaturated acids with high E-stereoselectivity under both microwave and conventional heating conditions with high TON and TOF values. This powerful approach efficiently demonstrated the utility of biomass derived aldehydes to build chemical agents used as fuel additives. The method proved to be scalable to gram scale synthesis.

A novel, mild and convenient method for the nitrodecarboxylation of substituted cinnamic acid derivatives to their nitroolefins is achieved using a catalytic amount of CuCl (10 mol%) and tert-butyl nitrite (2 equiv.) as a nitrating agent in the presence of air. This reaction provides a useful method for the synthesis of β,β-disubstituted nitroolefin derivatives, which are generally difficult to access from other conventional methods. Additionally, this reaction is selective as the E-isomer of the acid derivatives furnishes the corresponding E-nitroolefins. One more salient feature of the method is, unlike other methods, no metal nitrates or HNO3 are employed for the transformation.

The X-ray structure, synthesis, theoretical calculation and IR spectra of 1-naphthaleneacrylic acid are reported. The titled compound crystallizes in the monoclinic C 2/c space group with unit cell parameters: a = 14.556(3), b = 5.1332(10), c = 26.832(5) A , β = 97.02(3), V = 1989.8(7) A3, Z = 8 and form typical centrosymmetric hydrogen-bonded dimers. Theoretical calculations of 1-naphthylacrylic acid isolated molecule and hydrogen-bonded dimer have been carried out using density functional theory at the B3LYP level. For optimized structures the vibrational spectra have been then calculated and compared with experimental IR spectrum. The assignment and characterization of theoretical vibrational spectra were based on the potential energy distribution analysis. This comparison has shown that the theoretical spectrum for the dimer structure is in good agreement with the experimental one. Structural comparisons with naphthalene, and with some substituted 2-propenoic acids have shown influence of the substituent on conformation of the naphthalene ring or 2-propenoic moiety. Springer Science+Business Media, LLC 2012.

A novel type of cinnamic acid quinazoline amide derivatives (20-42), which designed the combination between quinazoline as the backbone and various substituted cinnamic acid as the side chain, have been synthesized and their biological activities were evaluated within cytotoxicity assay firstly and then potent EGFR inhibitory activity. Compound 42 demonstrated the most potent inhibitory activity (IC50 = 0.94 μM for EGFR), which could be optimized as a potential EGFR inhibitor in the further study. Docking simulation was performed to position compound 42 into the EGFR active site to determine the probable binding model. Analysis of the binding conformation of 42 in active site displayed compound 42 was stabilized by hydrogen bonding interactions with Lys822, which was different from other derivatives. In the further study, Compounds 43 and 44 had been synthesized and their biological activities were also evaluated, which were the same as that we expected. Compound 43 has demonstrated significant EGFR (IC50 = 0.12 μM) and tumor growth inhibitory activity as a potential anticancer agent.

A series of novel cinnamic acid metronidazole ester derivatives have been designed and synthesized, and their biological activities were also evaluated as potential EGFR and HER-2 kinase inhibitors. Compound 3h showed the most potent biological activity (IC50 = 0.62 μM for EGFR and IC50 = 2.15 μM for HER-2). Docking simulation was performed to position compound 3h into the EGFR active site to determine the probable binding model. Antiproliferative assay results demonstrated that some of these compounds possessed good antiproliferative activity against MCF-7. Compound 3h with potent inhibitory activity in tumor growth inhibition may be a potential anticancer agent.

A mixed catalyst K2PtCl4/AgOTf showed the highest activity for hydroarylation of propiolic acid, among palladium and platinum catalysts. This catalyst was effective for hydroarylation with less reactive benzene to give cis-cinnamic acid in good yield. The hydroarylation with toluene gave a higher yield of hydroarylation products than that with benzene and resulted in ortho/para orientation with an almost statistical ratio, suggesting that the result is very close to that of the Friedel-Crafts alkylation with methyl bromide or p-nitrobenzyl chloride. Hydroarylation of propiolic acid with other electron-rich arenes proceeded efficiently in the presence of the K2PtCl4/AgOTf catalyst in trifluoroacetic acid forming cis-cinnamic acids in good to high yields. This method was also applied to hydroarylation of ethyl propiolate.

Short and versatile syntheses of reusable diarylphosphinopolystyrene- supported palladium catalysts 3a-j are described. The bis(o-tolyl)phosphino catalyst 3b is particularly efficient for the Suzuki and Sonogashira cross-couplings, whereas the bis(m-tolyl)phosphino catalyst 3c is the most active catalyst for Heck reactions. The couplings are performed under non-anhydrous reaction conditions and require only low amounts of supported palladium (0.5 mequivs. for Suzuki-Miyaura, 1.0 mequiv. for Sonogashira and 0.5 mequivs. for Heck reactions could be sufficient). Catalysts 3a-j are recovered by filtration and can be reused more than four times with no loss of efficiency.

(E/Z)-Isomers containing vinyl bromides were stereoselectively carbonylated to the corresponding (E)-α,β-ethylenic carboxylic acids in the ionic liquid [BMIM]PF6. Vinyl dibromides also underwent hydroxycarbonylation to give monoacids. The products are pure by proton NMR spectroscopic determination without purification by silica gel column chromatograghy or recrystallization.

Piperazine as a new reagent for the condensation of aryl aldehydes and their bisulfite adducts with malonic acid are described which afford the corresponding cinnamic acids in excellent yields and short reaction times in the absence of solvents under microwave irradiation.

An attempt was made to synthesize a series of non-cytotoxic low molecular weight compounds of varying substitutions and functionalities having pharmacophore activity like carbonyl compounds, carboxylic acid and bioisosteres like tetrazole and phenyl acrylic acid. The in vitro assay of these analogues for the inhibition of complement activity revealed significant inhibitory activity for varying substituents and, particularly, for bioisosteres, that is, tetrazole and phenyl acrylic acid derivatives.

The Mizoroki-Heck reaction was carried out using a fluorous ether F-626 as the solvent and a fluorous Pd carbene complex as the catalyst. When carboxylic acids are the products, separation of both the F-626 and the Pd catalyst from the products can be conveniently carried out by simple filtration. The F-626 filtrates containing the Pd catalyst can be recycled.

3-Chloro-2-chlorocarbonylbenzo[b]thiophenes were obtained on oxidation of Meerwein reaction products, viz. 3-aryl-2-halopropionic acids and their esters, with thionyl chloride in the presence of N-benzyl-N-methylmorpholinium chloride. Disubstituted thioureas were synthesized by the reaction of these compounds with ammonium thiocyanate and aromatic amines, and were cyclized by interaction with iodoacetic acid with the formation of 4-thiazolidinone derivatives. The same cyclization in the presence of aromatic aldehydes leads to the formation of the corresponding 5-arylidene-substituted 4-thiazolidinones.

The Heck reaction of various aryl halides and alkenes took place in water in the presence of an amphiphilic polystyrene-poly(ethylene glycol) resin-supported palladium-phosphine complex to give the corresponding styrene derivatives in quantitative yields.

We recently described a novel aryl binding site of farnesyltransferase. The 2-naphthylacryloyl residue was developed as an appropriate substituent for our benzophenone-based AAX-peptidomimetic capable of occupying this binding site, resulting in a non-thiol farnesyltransferase inhibitor with nanomolar activity. The activity of this inhibitor is readily explained on the basis of docking studies which show the 2-naphthyl residue fitting into the aryl binding site.

The combustion-bomb calorimetry is used to determine the energies of combustion. The enthalpies of combustion and formation were calculated for seven cyclic derivatives of acrylic acid.

A number of novel styryl epoxides, N-substituted-styryl-ethanolamines, N-mono and N,N'-bis-(2-hydroxyethyl)-cinnamamides - analogues to the known radiosensitizers RSU- 1069, pimonidazole and etanidazole - display selective hypoxic radiosensitizing activity. The styryl group, especially when substituted by electron withdrawing groups, was found to be bioisosteric to the nitroimidazolyl functionality. The most active derivative 2-(2'-nitrophenyl)ethen-1-yl-oxirane 8a displayed a sensitizer enhancement ratio (SER) of 5 relative to misonidazole.

The reaction of arenesulphonyl chlorides (1a-n) with butyl acrylate (2a) in the presence of a catalytic amount of bis(benzonitrile)dichloropalladium under solid-liquid phase-transfer conditions gave the corresponding butyl(E)-3-arylprop-2-enoates (3a-n) in good yield.The alkenes (2b-g) could also be used in place of (2a).

The pKa values of 3-(1-naphthyl)propiolic acid, together with the 8-bromo- and 8-chloro-substituted derivative, and of (E)-3-(1-naphthyl)acrylic acid together with the 8-bromo- and 8-chloro-substituted derivatives, have been determined in 80percent (w/w) 2-methoxyethanol-water at 25 deg C.The rate coefficients for the esterification of these acids with diazodiphenylmethane have been measured in 2-methoxyethanol at 30 deg C.The rate coefficients for the alkaline hydrolysis of the corresponding methyl propiolates have been determined in 70percent (v/v) dioxane-water at both 30.0 and 50.1 deg C.In the ionisation and esterification reactions, reversed dipolar substituent effects were observed.The ΔpKa values are quantitatively accounted for either by comparison with the results for simple model compounds or by Kirkwood-Westheimer calculations.The retardations observed for the effect of 8-halo substituents in the alkaline hydrolysis reaction are in agreement with a reversed dipolar effect and no steric bulk effects are observed.

A series of 5-substituted 3,5-dihydroxypentanoic acids and their derivatives have been prepared and tested for inhibition of HMG-CoA reductase in vitro. In general, unless a carboxylate anion can be formed and the hydroxy groups remain unsubstituted in an erythro relationship, inhibitory activity is greatly reduced. Furthermore, only one enantiomer of the ring-opened form of lactone 6a(±) possesses the activity displayed by the racemate. Insertion of a bridging unit other than ethyl or (E)-ethenyl between the 5-carbinol moiety and an appropriate lipophilic moiety (e.g., 2,4-dichlorophenyl) attenuates activity.

A new method for the preparation of naphtho- and naphthothiophene structures by arylation of acrylic acid with α- and β-iodonaphthalene and subsequent oxidation of the resulting trans-naphthylacrylic acids with thionyl chloride in the presence of triethylbenzylammonium chloride is proposed.

-