- Preparation method of (E,E,Z)-10, 12, 14-hexadecatriene acetate, composition and attractant core
-
The invention relates to a preparation method of (E,E,Z)-10,12,14-hexadecatriene acetate, a Diaphania pyloalis attractant composition and an attractant core, and compared with the prior art, the preparation method of (E,E,Z)-10,12,14-hexadecatriene acetate has the advantages of cheap and easily available raw materials, high reaction yield, simple post-treatment, high isomerization purity of the synthesized compound, clean and environment-friendly process flow, and high activity in field. The Diaphania pyloalis attractant composition based on the (E,E,Z)-10,12,14-hexadecatriene acetate and theattractant core of the Diaphania pyloalis attractant composition have a remarkable moth-luring synergistic effect and can be stably and efficiently used for population monitoring, prevention and control of mulberry borers.
- -
-
Paragraph 0025; 0049-0051; 0061-0062
(2021/02/10)
-
- N-Substituted Valiolamine Derivatives as Potent Inhibitors of Endoplasmic Reticulum α-Glucosidases I and II with Antiviral Activity
-
Most enveloped viruses rely on the host cell endoplasmic reticulum (ER) quality control (QC) machinery for proper folding of glycoproteins. The key ER α-glucosidases (α-Glu) I and II of the ERQC machinery are attractive targets for developing broad-spectrum antivirals. Iminosugars based on deoxynojirimycin have been extensively studied as ER α-glucosidase inhibitors; however, other glycomimetic compounds are less established. Accordingly, we synthesized a series of N-substituted derivatives of valiolamine, the iminosugar scaffold of type 2 diabetes drug voglibose. To understand the basis for up to 100,000-fold improved inhibitory potency, we determined high-resolution crystal structures of mouse ER α-GluII in complex with valiolamine and 10 derivatives. The structures revealed extensive interactions with all four α-GluII subsites. We further showed that N-substituted valiolamines were active against dengue virus and SARS-CoV-2 in vitro. This study introduces valiolamine-based inhibitors of the ERQC machinery as candidates for developing potential broad-spectrum therapeutics against the existing and emerging viruses.
- Aakula, Balakishan,Hill, Michelle L.,Karade, Sharanbasappa S.,Kiappes, J. L.,Manne, Rajkumar,Mariuzza, Roy A.,Treston, Anthony M.,Warfield, Kelly L.,Zitzmann, Nicole
-
p. 18010 - 18024
(2021/12/17)
-
- 3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia
-
Male ithomiine butterflies (Nymphalidae: Danainae) have hairpencils on the forewings (i.e., androconia) that disseminate semiochemicals during courtship. While most ithomiines are known to contain derivatives of pyrrolizidine alkaloids, dihydropyrrolizines, or ?-lactones in these androconia, here we report on a new class of fatty acid esters identified in two subspecies, Ithomia salapia aquinia and I. s. derasa. The major components were identified as isoprenyl (3-methyl-3-butenyl) (Z)-3-acetoxy-11-octadecenoate, isoprenyl (Z)-3-acetoxy-13-octadecenoate (12) and isoprenyl 3-acetoxyoctadecanoate (11) by GC/MS and GC/IR analyses, microderivatizations, and synthesis of representative compounds. The absolute configuration of 12 was determined to be R. The two subspecies differed not only in the composition of the ester bouquet, but also in the composition of more volatile androconial constituents. While some individuals of I. s. aquinia contained ithomiolide A (3), a pyrrolizidine alkaloid derived ?-lactone, I. s. derasa carried the sesquiterpene a-elemol (8) in the androconia. These differences might be important for the reproductive isolation of the two subspecies, in line with previously reported low gene exchange between the two species in regions where they co-occur. Furthermore, the occurrence of positional isomers of unsaturated fatty acid derivatives indicates activity of two different desaturases within these butterflies, ?9 and ?11, which has not been reported before in male Lepidoptera.
- Elias, Marianne,Mann, Florian,McClure, Melanie,Schulz, Stefan,Silva, Lisa de,Szczerbowski, Daiane
-
supporting information
p. 2776 - 2786
(2020/12/29)
-
- Tandem IBX-Promoted Primary Alcohol Oxidation/Opening of Intermediate β,γ-Diolcarbonate Aldehydes to (E)-γ-Hydroxy-α,β-enals
-
A tandem IBX-promoted oxidation of primary alcohol to aldehyde and opening of intermediate β,γ-diolcarbonate aldehyde to (E)-γ-hydroxy-α,β-enal has been developed. Remarkably, the carbonate opening delivered exclusively (E)-olefin and no over-oxidation of γ-hydroxy was observed. The method developed has been extended to complete the stereoselective total synthesis of both (S)- and (R)-coriolides and d-xylo- and d-arabino-C-20 guggultetrols.
- Kumari, Anupama,Gholap, Sachin P.,Fernandes, Rodney A.
-
p. 2278 - 2290
(2019/06/17)
-
- Method for preparing sex pheromone of spodoptera litura
-
The invention discloses a method for preparing sex pheromone of spodoptera litura. The method comprises the following steps of S1, synthesizing 9-bromo-1 sterol; S2, synthesizing triphenyl phosphorusbromide quaternary ammonium salt under nitrogen protection; S3, synthesizing 9,11-tetradecadiene-1-one alcohol; S4, synthesizing (Z,E)-9,11-tetradecadiene-1 alcohol; S5, synthesizing (Z,E)-9,11 tetracarbondiene-1 alcohol acetate. The method adopts cheap and easily available 1,9-nonanediol as a raw material to react with a 48% HBr aqueous solution, and obtains the 9-bromo 1 decyl alcohol in a 90% yield, the yield of a single bromide 9-bromo-1 sterol is higher, finally (Z, E)-9,11-tetradecadienyl alcohol is reacted with acetic anhydride and pyridine to synthesize a (Z, E)-9,11-tetradecadiene-1 alcohol ester, and a purity is up to 99.2%; according to the method, a solvent is distilled off by reducing a pressure, a residue is subjected to a rapid silica gel column chromatography, and a purification method is low in cost and suitable for large-scale promotion.
- -
-
Paragraph 0019
(2019/04/26)
-
- SYNTHESIS OF ATTRACTANT OF PISTACHIO TWIG BORER (KERMANIA PISTACIELLA)
-
The present invention relates to the stereoselective synthesis (2S,12Z)-2-acetoxy-12-heptadecene secreted by female pistachio twig borer and attract male individuals.
- -
-
Page/Page column 3; 4
(2017/11/03)
-
- Synthesis of specific deuterated derivatives of the long chained stratum corneum lipids [EOS] and [EOP] and characterization using neutron scattering
-
The synthesis of specific deuterated derivatives of the long chained ceramides [EOS] and [EOP] is described. The structural differences with respect to the natural compounds are founded in the substitution of the 2 double bonds containing linoleic acid by a palmitic acid branched with a methyl group in 10-position. The specific deuteration is introduced both in the branched and in the terminal methyl group, which was realized by common methods of successive deuteration of carboxylic groups in 3 steps. These modified fatty acids resp. the corresponding ceramides [EOS] and [EOP] were prepared for neutron scattering investigations. First results of these investigations were presented in this manuscript showing that the deuterated compounds could be detected in the stratum corneum lipid model membranes. The deuterated ceramides [EOS] and [EOP] are valuable tools to investigate the influence of these long chained ceramide species on the nanostructure of stratum corneum lipid model membranes.
- Sonnenberger, Stefan,Eichner, Adina,Schmitt, Thomas,Hau?, Thomas,Lange, Stefan,Langner, Andreas,Neubert, Reinhard H.H.,Dobner, Bodo
-
p. 316 - 330
(2017/06/08)
-
- A compound and its preparation method and application
-
The invention discloses a new compound with a structure shown in the formula A. The new compound is an impurity generated in the preparation process of steride antiestrogens, such as fulvestrant and the like. The invention discloses a source capable of generating the new compound and a preparation method of the new compound. According to the preparation method, the impurity can be conveniently distinguished when the steride antiestrogens are synthesized, so that a method for decreasing or preventing the generation of the impurity is found.
- -
-
Paragraph 0042
(2017/08/24)
-
- Fulvestrant process for the preparation of intermediates
-
The invention provides a preparation method of a fulvestrant intermediate. The preparation method of the fulvestrant intermediate is characterized in that a water extraction starting material 1,9-nonanediol is adopted for controlling the content of 1,8-octylene glycol, an antioxidant is added for reducing byproducts which are generated by Michael addition and difficult to purify and pH value is regulated for reducing production of aromatized impurities difficult to remove, so that a route for preparing fulvestrant by virtue of the fulvestrant intermediate has the advantages that a final product is difficult to purify, the cost is low and industrialization can be easily realized. The prepared fulvestrant intermediate lays a key foundation for obtaining a route for synthesizing fulvestrant which is easy to purify and easy for industrialization.
- -
-
Paragraph 0069; 0070
(2017/03/08)
-
- A new method for the synthesis of fulvestrant (by machine translation)
-
The invention discloses a new method for the synthesis of fulvestrant, it is in order to intermediate X and five fluorine amyl alcohols as the starting material as the starting material, obtained through the four-step reaction of fulvestrant, this line does not need to column chromatography purification, the crude final product only needs to re-crystallization can be obtained the fulvestrant accord with Pharmacopoeia standards, overall yield is 50 the [...] 60%, and the raw material are industrial product, is easy to obtain, the quality is easy to control. (by machine translation)
- -
-
Paragraph 0044; 0046
(2018/02/04)
-
- Long-chain alkyltriazoles as antitumor agents: Synthesis, physicochemical properties, and biological and computational evaluation
-
A series of novel long-chain alkyltriazoles were prepared from commercial diols in a rapid process with good yields. The compounds were evaluated in vitro for their anticancer potential against two human cancer cell lines: colon carcinoma (RKO) and uterine carcinoma (HeLa). The results of colorimetric MTT assays showed that six of fourteen compounds tested decreased cell viability in these cell lines. Compounds 5e and 6a were the most active against RKO cells, with IC50 values of 16.70 and 14.57 μM, respectively. The same compounds, 5e and 6a, were the most active in HeLa cells as well, with IC50 values of 11.05 and 12.77 μM, respectively. In addition, compound 5e was found to induce apoptosis in RKO cells, as assessed by TUNEL assay. The results suggest that compound 5e may be a promising prototype anticancer agent.
- Gontijo, Vanessa Silva,Oliveira, Michael der,Resende, Rafael Jos,Fonseca, Amanda Luisa,Nunes, Renata Rachide,Jnior, Moacyr Comar,Taranto, Alex Gutterres,Torres, Natalia Machado Pereira Oliveira,Viana, Gustavo Henrique Ribeiro,Silva, Luciana Maria,Alves, Rosemeire Brondi,Varotti, Fernando Pilla,Freitas, Rossimiriam Pereira
-
p. 430 - 441
(2015/03/31)
-
- Identification and synthesis of the male produced volatiles of the carrion beetle, Oxelytrum erythrurum (Coleoptera: Silphidae)
-
Necrophagous beetles belonging to the family Silphidae are recognized as potentially useful in forensic investigations (to estimate post mortem interval). Gas chromatography analyses of extracts of aerations of adult Oxelytrum erythrurum revealed the presence of two male-specific compounds. These compounds were identified as (Z)-1,10-nonadecadiene (major) and 1-nonadecene (minor) using microderivatizations of the natural male extract, such as hydrogenation, partial reduction and methylthiolation, mass spectrum comparisons, and co-injections with authentic standards. Both compounds might be components of a pheromone responsible for sexual communication in this species.
- Fockink, Douglas H.,Martins, Camila B.C.,Zarbin, Paulo H.G.
-
p. 5353 - 5356
(2015/09/01)
-
- New fluorinated agonists for targeting the sphingosin-1-phosphate receptor 1 (S1P1)
-
The sphingosine-1-phosphate receptor type 1 (S1P1) is involved in fundamental biological processes such as regulation of immune cell trafficking, vascular barrier function and angiogenesis. This Letter presents multistep syntheses of various fluorine substituted 12-aryl analogues of the drug fingolimod (FTY720) and a seven-steps route to 2-amino-17,17-difluoro-2-(hydroxymethyl)heptadecan-1-ol. In vitro and in vivo tests proved all these compounds as potent S1P1 receptor agonists.
- Shaikh, Rizwan S.,Keul, Petra,Sch?fers, Michael,Levkau, Bodo,Haufe, Günter
-
supporting information
p. 5048 - 5051
(2015/11/09)
-
- Leishmanicidal, antiproteolytic, and mutagenic evaluation of alkyltriazoles and alkylphosphocholines
-
Abstract A series of 16 simple long-chain alkyltriazoles and two novel alkylphosphocholine derivatives containing an azide moiety were evaluated in vitro for their leishmanicidal activity against. Among the 18 compounds tested, the eight most active compounds against promastigote forms were selected for further evaluation against amastigote forms. These compounds were also evaluated for their cytotoxicity against murine macrophages and tested as inhibitors of cysteine protease rCPB2.8, an important target for development of antileishmanial drugs. The mutagenicity of some of these compounds was also evaluated in prokaryotic and eukaryotic cells to assess any genetic effects of the leishmanicidal candidates. The compound 4, an alkylphosphocholine derivative, was found to be the most potent against amastigote forms with an IC50 of 3.81 μM, comparable to that of pentamidine (IC50 = 6.62 μM) and amphotericin B (IC50 = 6.10 μM), two established leishmanicidal drugs. Compound 4 also exhibited the best selectivity index (SI) values of the series, demonstrating low toxicity against macrophages and a cLogP value higher than 5. Among the alkyltriazoles, compounds 13 and 14 were the most active against promastigote and amastigote forms. They were then evaluated for their mutagenicity in vitro; the mutagenicity index (MI) values were lower than 2, suggesting that these compounds are not mutagenic.
- Gontijo, Vanessa Silva,Espuri, Patrícia Ferreira,Alves, Rosemeire Brondi,De Camargos, Luiz Fernando,Dos Santos, Fábio Vieira,De Souza Judice, Wagner Alves,Marques, Marcos José,Freitas, Rossimiriam Pereira
-
-
- A facile asymmetric synthesis of (S)-14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth
-
An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth has been achieved. The target molecule was synthesized in six linear steps and in 30.3% overall yield from commercially available hexanoyl chloride, (S)-4-benzyloxazolidin-2-one and 1,9-nonanediol. The hexanoyl chloride was connected with (S)-4-benzyloxazolidin-2-one, and with the induction of the chiral oxazolidinone auxiliary, after chiral methylation, LAH reduction and then tosylation gave the chiral key intermediate 5 in high stereoselectivity. 1,9-Nonanediol, was selectively brominated, THP protected and subjected to Li2CuCl4-mediated C-C coupling to afford a C12 intermediate. The target molecule, (S)-14-methyl-1-octadecene, was obtained after the two parts were subjected to a second Li 2CuCl4-mediated C-C coupling. Our synthetic approach represents the first time a substrate-control asymmetric synthesis of (S)-14-methyl-1-octadecene has been reported.
- Zhang, Tao,Ma, Wei-Li,Li, Tian-Rui,Wu, Jia,Wang, Jun-Run,Du, Zhen-Ting
-
p. 5201 - 5208
(2013/06/27)
-
- Molecular design, synthesis, and evaluation of novel potent apoptosis inhibitors inspired from bongkrekic acid
-
Bongkrekic acid (BKA) is an inhibitor of adenine nucleotide translocase (ANT). Since inhibition of ANT is connected to the inhibition of cytochrome c release from mitochondria, which then results in the suppression of apoptosis, it has been used as a tool for the mechanistic investigation of apoptosis. BKA consists of a long carbon chain with two asymmetric centers, a nonconjugated olefin, two conjugated dienes, three methyl groups, a methoxyl group, and three carboxylic acids. This complicated chemical structure has caused difficulties in synthesis, supply, and biochemical mechanistic investigations. In this study, we designed and synthesized more simple tricarboxylic acids that were inspired by the molecular structure of BKA. Their cytotoxicity and apoptosis-preventing activity in HeLa cells and the effect on the mitochondrial inner membrane potential (Δψm) in HL-60 cells were then evaluated. All tested tricarboxylic acid derivatives including BKA showed little toxicity against HeLa cells. BKA and two of the synthesized derivatives significantly suppressed staurosporine (STS)-induced reductions in cell viability. Furthermore, STS-induced Δψm collapse was significantly restored by pretreatment with BKA and a tricarboxylic acid derivative. Other derivatives, in which one of three carboxylic acids was esterified, exhibited potent toxicity, especially a derivative bearing a carbon chain of the same length as that of BKA. In conclusion, we have developed a new lead compound as an apoptosis inhibitor bearing three carboxylic acids connected with the proper length of a long carbon chain.
- Okuda, Katsuhiro,Hasui, Keisuke,Abe, Masato,Matsumoto, Kenji,Shindo, Mitsuru
-
p. 2253 - 2260
(2013/01/15)
-
- Potent oligomerization and macrocyclization activity of the thioesterase domain of vicenistatin polyketide synthase
-
The thioesterase domain of the polyketide synthase involved in the biosynthesis of the 20-membered macrolactam antibiotic vicenistatin (VinTE) was found to catalyze oligomerization and macrocyclization of ω-hydroxy fatty acid ethyl esters to afford 17-28-membered macrocyclic lactones. The ring sizes of the macrocycles appear to be limited to the more moderate sizes because of the space limitation of the active site of VinTE. It was also verified that the initially formed linear dimer is first released from the active site of VinTE and then is recognized again by VinTE prior to its transformation to the cyclic dimer.
- Kudo, Fumitaka,Asou, Yusaku,Watanabe, Moe,Kitayama, Takashi,Eguchi, Tadashi
-
p. 1843 - 1846
(2012/08/29)
-
- Synthesis and Evaluation of Antimalarial Activity of Oxygenated 3-alkylpyridine Marine Alkaloid Analogues
-
A series of new oxygenated analogues of marine 3-alkylpyridine alkaloids were prepared from 3-pyridinepropanol in few steps and in good yields. The key step for the synthesis of these compounds was a Williamson etherification under phase-transfer conditions. All new compounds were evaluated for their antiplasmodial activity and cytotoxicity. A significant reduction in parasitaemia was observed for some of the prepared compounds, and the majority of them exhibited a selectivity index (SI) ranging from 2.78 to 15.58, which suggests that these compounds may be a promising class of substances with antimalarial activity.
- Hilario, Flaviane F.,de Paula, Renata Cristina,Silveira, Mariana L. T.,Viana, Gustavo H. R.,Alves, Rosemeire B.,Pereira, Juliana R.C.S.,Silva, Luciana Maria,de Freitas, Rossimiriam P.,de Pilla Varotti, Fernando
-
scheme or table
p. 477 - 482
(2012/04/04)
-
- Fulvestrant: From the laboratory to commercial-scale manufacture
-
The development of a commercial manufacturing process for fulvestrant (the active ingredient in 'Faslodex') is described. Key steps in the synthesis are stereoselective 1,6-addition of an organocuprate to a steroidal dienone followed by copper-mediated aromatisation of the A-ring. The strategy for dealing with noncrystalline intermediates is outlined. The production of drug substance of acceptable quality is critically dependent on limiting the formation of key impurities. The origin of these impurities is discussed, and measures to prevent or control their formation are described.
- Brazier, Eve J.,Hogan, Philip J.,Leung, Chiu W.,O'Kearney-McMullan, Anne,Norton, Alison K.,Powell, Lyn,Robinson, Graham E.,Williams, Emyr G.
-
experimental part
p. 544 - 552
(2011/07/30)
-
- Reductive deprotection of silyl groups with Wilkinson's catalyst/catechol borane
-
Traditionally silyl groups are deprotected with acids and fluorides. These methods are, however, less discriminating when multi-silyl groups are present in the same molecule, resulting in lower yields of the desired products. The manipulation of these functions during the total synthesis of natural products, for example, prostaglandins and isoprostanes, requires the selective protection and deprotection of these groups. We are reporting here on a mild, selective and efficient method for the reductive deprotection of silyl groups using Wilkinson's catalyst/catechol borane or catechol borane alone.
- Patel, Pranav,Chang, Chih-Tsung,Kang, Namin,Lee, Gue-Jae,Powell, William S.,Rokach, Joshua
-
p. 5289 - 5292
(2008/02/09)
-
- Synthesis and mass spectrometric analysis of cyclostellettamines H, I, K and L
-
Very recently the new cyclostellettamines H, I, K and L were identified from a Brazilian sponge of the genus Pachychalina. They were isolated together with the known cyclostellettamines A-G in a mixture of only 1.5 mg. To obtain further material for biological investigations, the synthesis of the four new cyclostellettamines has been carried out. Since mass spectrometry plays an essential role in identifying these compounds a systematic analysis of the cyclostellettamines is discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Grube, Achim,Timm, Christoph,Koeck, Matthias
-
p. 1285 - 1295
(2007/10/03)
-
- Synthesis and characterization of 3,13- and 2,13-octadecadienyl compounds for identification of the sex pheromone secreted by a clearwing moth, Nokona pernix
-
Several geometrical isomers of 3,13- and 2,13-octadecadien-1-ols and their acetates were synthesized starting from 1,8-octanediol or 1,9-nonanediol utilizing acetylene coupling reactions. In addition to commercially available compounds, all geometrical isomers of each dienyl compound were analyzed by NMR and GC-MS to accumulate chemical data for studies of sex pheromones secreted from clearwing moths classified into the family Sesiidae of Lepidoptera. Although acetoxy derivatives of the 3,13- and 2,13-dienes showed almost the same mass spectra, the alcohols were distinguished by comparing the relative intensities of [M - 18]+ at m/z 248, indicating direct differentiation of the two positional isomers without derivatization. Furthermore, each geometrical isomer eluted from a high-polar GC column with a different retention time. Base on these data, a pheromone gland extract of a sesiid moth, Nokona pernix, was analyzed by GC-EAD and GC-MS, and two EAG-active components were identified, viz., the (3E,13Z)- and (3Z,13Z)-isomers of 3,13-octadecadien-1-ol in a ratio of 9:1. In the field, the synthetic compounds mixed in 9:1 ratio attracted N. pernix males well, while a single component scarcely attracted the males. The number of attracted males peaked in the middle of June, and a small second peak was observed in August.
- Naka, Hideshi,Nakazawa, Tomotake,Sugie, Mieko,Yamamoto, Masanobu,Horie, Yoshiteru,Wakasugi, Ryohei,Arita, Yutaka,Sugie, Hajime,Tsuchida, Koji,Ando, Tetsu
-
p. 508 - 516
(2008/02/10)
-
- Effects of indole fatty alcohols on the differentiation of neural stem cell derived neurospheres
-
In a search for inducers of neuronal differentiation to treat neurodegenerative diseases such as Alzheimer's disease, a series of indole fatty alcohols (IFAs) were prepared, 13c (n = 18) was able to promote the differentiation of neural stem cell derived neurospheres into neurons at a concentration of 10 nM. Analysis of the expression of the Notch pathway genes in neurospheres treated during the differentiation phase with 13c (n = 18) revealed a significant decrease in the transcription of the Notch 4 receptor.
- Coowar, Djalil,Bouissac, Julien,Hanbali, Mazen,Paschaki, Marie,Mohier, Eliane,Luu, Bang
-
p. 6270 - 6282
(2007/10/03)
-
- Silyl group deprotection by Pd/C/H2. A facile and selective method
-
An easy, high yield, RT, short-reaction-time Pd/C hydrogenation of silyl groups is described. This includes TES, TPS, TBS, TBDMS, TIPS, and TBDPS. The relative selectivity of the process has been investigated and we can show, for example, that TES, TPS, TBS, and TBDMS removal can be performed in the presence of TIPS and TBDPS.
- Kim, Seongjin,Jacobo, Sheila Marie,Chang, Chih-Tsung,Bellone, Sophie,Powell, William S.,Rokach, Joshua
-
p. 1973 - 1976
(2007/10/03)
-
- Synthesis and 19F NMR study of RF-oleic acid-F13
-
A seven-step synthesis of Z-13,13,14,14,15,15,16,16,17,17,18,18, 18-tridecafluoro-octadec-9-enoic acid (oleic acid-F13) is reported. The key step is a Wittig reaction to form the C9-C10 double bond with a Z:E isomeric ratio greater than 20:1. The 19F nuclear magnetic resonance (NMR) spectrum is included and unambiguous assignments have been made with the aid of 19F-19F correlation NMR spectroscopy (COSY spectra).
- Buchanan, Gerald W.,Smits, Rufus,Munteanu, Elena
-
p. 255 - 259
(2007/10/03)
-
- Functional group transformations of diols, cyclic ethers, and lactones using aqueous hydrobromic acid and phase transfer catalyst under microwave irradiation
-
Synthesis of bromoalkanols has been achieved from diols, ethers, and lactones using aq HBr (48%) and tetrabutylammonium iodide/bromide as phase transfer catalyst under microwave irradiation. This environmentally benign route provides enhanced yields of products and does away with the use of benzene as compared to existing conventional methods.
- Kad, Goverdhan L.,Kaur, Irvinder,Bhandari, Monica,Singh, Jasvinder,Kaur, Jasamrit
-
p. 339 - 340
(2013/09/06)
-
- Monolayers as models for supported catalysts: Zirconium phosphonate films containing manganese(III) porphyrins
-
Organized monolayer films of a manganese tetraphenylporphyrin have been prepared and used as supported oxidation catalysts. Manganese 5,10,15,20- tetrakis(tetrafluorophenyl-4′-octadecyloxyphosphonic acid) porphyrin (1) has been immobilized as a monolayer film by a combination of Langmuir-Blodgett (LB) and self-assembled monolayer techniques that use zirconium phosphonate linkages to bind the molecule to the surface. Analysis by FTIR, XPS, UV - vis and polarized optical spectroscopy show that the films consist of noninteracting molecules effectively anchored and oriented nearly parallel to the surface. The monolayer films are stable to the solvent and temperature conditions needed to explore organic oxidations. The activity of films of 1 toward the epoxidation of cyclooctene using iodosylbenzene as the oxidant was compared to that of Manganese 5,10,15,20- tetrakis(pentafluorophenyl) porphyrin (2) and 1 under equivalent homogeneous conditions. The immobilized porphyrin 1 shows an enhanced activity relative to either homogeneous reaction. The main difference between 1 and 2 is the four alkyl phosphonate arms in 1 designed to incorporate the porphyrin within the films. The increased activity of immobilized 1 is a combination of the porphyrin structure, which prohibits the formation of μ-oxo dimers even in solution, and a change in conformation when anchored to the surface. The study demonstrates that careful monolayer studies can provide useful models for the design and study of supported molecular catalyst systems.
- Benitez, Isa O.,Bujoli, Bruno,Camus, Laurent J.,Lee, Christine M.,Odobel, Fabrice,Talham, Daniel R.
-
p. 4363 - 4370
(2007/10/03)
-
- A convenient route to alkaloid lipids: Application for the synthesis of a leptophylline A analogue
-
A synthetic route for efficient access to alkaloid lipids, using the chiral 2,3,6-trisubstituted piperidine acetaldehyde 9 as an intermediate, is reported. The utility of the synthetic route was demonstrated in the asymmetric synthesis of an unnatural analogue of Cassia leptophylla alkaloid lipid, leptophyllin A, in 16 steps and 15% overall yield starting from D-glucal.
- Koulocheri,Pitsinos,Haroutounian
-
p. 111 - 115
(2007/10/03)
-
- Synthesis of dideuterated and enantiomers of monodeuterated tridecanoic acids at C-9 and C-10 positions
-
We report a route for the preparation of mono and dideuterated tridecanoic acids: (R)-[9-2H1]-,(S)-[9-2H1]-,(R)-[10-2H1]-,(S)-[10-2H1]-,[9,9-2H2]-, and [10,10-2H2]-tridecanoic acids required as probes for biochemical studies on desaturases. The key intermediates in the synthesis of all these probes are ketones 9, which give rise to the corresponding alcohols 10 and 13 by reduction with LiAlD4 and LiAlH4, respectively. Derivatization of nondeuterated racemic alcohols 13 with (S)-(+)-9-anthranylmethoxyacetic acid ((S)-(+)-9-AMA) and chromatographic resolution of both diastereoisomers allowed us to determine the absolute configuration of the stereogenic centers by 1H NMR using an adaptation of the model proposed by Riguera and co-workers which was validated with alcohols of known absolute configuration. Both enantiomeric alcohols (R)- and (S)-13 were recovered by reduction of each diastereomeric ester with LiAlH4. Mesylation of alcohols 10 and 13 followed by nucleophilic substitution by LiAlD4 generated the saturated methoxymethyl derivatives 12 and 16, respectively. Final deprotection and Jones oxidation of the resulting alcohols afforded the above deuterated tridecanoic acids.
- Abad,Fabrias,Camps
-
p. 8582 - 8588
(2007/10/03)
-
- Studies related to in vivo C-H activation: Synthesis and influence of 8,8- and 11,11-dimethyl oleic and 11,11-dimethyl linoleic acids on Δ12- desaturation of C. sorokiniana
-
The synthesis of three acids was achieved using the Wittig reaction in order to study their in vivo influence on the Δ12-desaturase of Chlorella sorokiniana. It was shown that the introduction of two methyls near the double bond prevent the desaturation of these exogenous acids while they seem to be accurately incorporated. This functionality could be of interest for the design of new thiaoleic acids as probes of the different oxidation processes.
- Poulain, Sophie,Noiret, Nicolas,Fauconnot, Laetitia,Nugier-Chauvin, Caroline,Patin, Henri
-
p. 3595 - 3604
(2007/10/03)
-
- The First Total Synthesis of Tricolorin A
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Keywords: glycosylations; macrocycles; one-pot reactions; total synthesis; tricolorin A
- Lu, Shou-Fu,O'yang, QinQin,Guo, Zhong-Wu,Yu, Biao,Hui, Yong-Zheng
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p. 2344 - 2346
(2007/10/03)
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- Total synthesis of tricolorin A
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Tricolorin A (1), a structurally amazing resin glycoside with promising bioactivities from Ipomoea tricolor cav. (convolvulaceae), was synthesized in a total of 45 steps, with the longest linear sequence of 20 steps and overall yield of 0.65% from D-mannitol. The AB disscharide 19-membered lactone 2 was constructured by a regioselective macrolactonization using Corey-Nicolaou protocol. The macrolactone tetrasaccharide 33 was realized either by 'one- pot two-step' glycosylation procedure or by a stepwise assembly employing the 'armed-disarmed' glycosylation strategy.
- Lu, Shou-Fu,O'Yang, QinQin,Guo, Zhong-Wu,Yu, Biao,Hui, Yong-Zheng
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p. 8400 - 8405
(2007/10/03)
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- Diastereoselective and convergent synthesis of both 11′-epimers of (-)-(2R,3R,6S)-carnavaline
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Enantio- and diastereoselective syntheses of both 11′-epimers of (-)-carnavaline 1 have been achieved. Since the configuration of the remote chiral centre in the C-12 side chain of naturally occurring (-)-carnavaline had been unknown and spectroscopic data were not conclusive, an assignment of the 11′S-epimer to the natural product by comparison of the melting points is discussed and complete spectroscopic data are given.
- Pahl, Axel,Oetting, Joerg,Holzkamp, Jens,Meyer, Hartmut H.
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p. 7255 - 7266
(2007/10/03)
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- Design and synthesis of analogues of ionomycin
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Based on the analysis of the crystal structure of the Ca2+ salt of ionomycin and the chemical and physical data on ionomycin, a number of ionomycin analogues have been synthesized to study the structural features affecting the Ca2+ binding and transport. Compounds 2, 3, and 4 were synthesized to study the effect of additional intramolecular oxygen coordination sites on Ca2+ transport. Compounds 5a-5d were prepared to study the effect of lipid solubility on Ca2+ binding and transport. Compounds 6a-6c were prepared to study the effect of the distance between the β-diketone and the carboxyl group on Ca2+ transport. A general synthetic route to these compounds has been developed. The key reactions in this route are the consecutive regioselective alkylations of the dianion of 2,4-pentanedione with the appropriate bromides.
- Hu,Weiler
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p. 1500 - 1511
(2007/10/02)
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- The synthesis of natural R-(-)enantiomers from three galbanum resin macrolides
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The three macrolides 1, 2 and 3 isolated from galbanum resin were synthesized starting from ω-bromoacetals 9. The key step is the buffered intramolecular Wittig reaction of the ylides 14 and 23 to afford the α,β-unsaturated lactones 15, 16 and 24. Hydrogenation of these lactones gives the title macrolides in (R)-configuration.
- Bestmann,Kellermann
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p. 1257 - 1261
(2007/10/02)
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- A New Synthetic Method of Macrocyclic Lactones from ω-Iodoalkylacrylates
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When the photostimulated cyclization reaction of ω-iodoalkylacrylates was performed in the presence of metal hydride complexes such as sodium cyanoborohydride (NaBH3CN), sodium borohydride (NaBH4) and potassium borohydride (KBH4), the corresponding macrocyclic lactones were produced.The use of NaBH3CN led to the highest yield of lactones.
- Abe, Motoji,Hayashikoshi, Takaoki,Kurata, Takeo
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p. 1789 - 1792
(2007/10/02)
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- Free Radical Macrocyclisation via Propiolate Esters.
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Intramolecular free-radical addition to propiolate esters has provided a new and stereoselective route to 14-16 membered trans-α,β-unsaturated macrocyclic lactones from their corresponding ω-iodoalkyl-propiolate esters under triphenyltin hydride/AIBN mediated conditions.Attempts to synthesise analogous 10-13 membered lactones proved unsuccessful, resulting in acyclic products derived from direct reduction at the radical centre. Key words: Radical; macrocyclisation; propiolate ester; macrocyclic unsaturated lactone; high dilutionm
- Baldwin, Jack E.,Adlington, Robert M.,Ramcharitar, Steve H.
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p. 3413 - 3428
(2007/10/02)
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- The synthesis of β-keto lactones via cyclization of β-keto ester dianions or the cyclization of Meldrum's acid derivatives
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Two new methods to synthesize macrocyclic β-keto lactones have been developed.The first involves the synthesis of ω-halo-β-keto esters and an intramolecular alkylation of the dianions to these compounds.The reaction is complicated by elimination in the small and medium ring systems and by difficulties in purifying the final products.However, it is possible to obtain modest yields of the desired β-keto lactones.This procedure was used to synthesize the 25- and 27-membered ring β-hydroxy lactones that are the constituents of termite defense compounds.The second method involves the thermolysis of acylated Meldrum's acid derivatives, which leads directly to β-keto lactones.This process gives modest yields of macrocyclic systems and good yield of the unsubstituted 3-oxopentan-5-olide (25) .The 14-membered macrocyclic β-keto lactone 9j has a complex 1H NMR spectrum, which has been interpreted in terms of multiple conformations.The temperature dependence of the NMR spectrum of 9j is consistent with entropic, rather than enthalpic, control of the equilibrium.Quasiharmonic entropy calculations are consistent with this model.
- Lermer, Leonard,Neeland, Edward G.,Ounsworth, James P.,Sims, Russell J.,Tischler, Samuel A.,Weiler, Larry
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p. 1427 - 1445
(2007/10/02)
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- Synthesis of Large Macrocyclic Tetraaza Compounds with A Methylene Backbone: Cyclo4, (n = 6,7,8,9 and 10). The Formation of 28-, 32-, 36-, 40- and 44-Membered Rings.
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A series of macrocyclic tetraamines with 28-, 32-, 36-, 40- and 44-membered rings have been efficiently prepared from the corresponding ditosylamide and monobromoalcohol derivatives in 6 steps via a double condensation reaction.Overall yields were: 41, 41, 46, 29, and 33 percent, respectively, for 1,8,15,22-tetraazacyclooctacontane (11a), 1,9,17,25-tetraazacyclodotriacontane (11b), 1,10,19,28, tetraazacyclohexatriacontane (11c), 1,11,21,31-tetraazacyclotetracontane (11d) and 1,12,23,34-tetraazacyclotetratetracontane (11e).
- Tomohiro, Takenori,Uoto, Kouichi,Okuno, Hiroaki (Yohmei)
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p. 1233 - 1239
(2007/10/02)
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- Design, synthesis, and activity of membrane-disrupting bolaphiles
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Four new classes of bolaphiles ("double-headed" single-chain surfactants) have been prepared, via condensation of an homologous series of linear saturated, olefinic, and acetylenic α,ω-dicarboxylic acids with hexaethylene glycol, and evaluated for their ability to induce the release of 5(6)-carboxyfluorescein (CF) entrapped within large unilamellar vesicles derived from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Operationally, the membrane-disrupting activity of the bolaphiles has been found to vary by a factor of ca. 100, when the total number of carbon atoms which separate the carboxylate moieties range from 12 to 24; the most active bolaphile is approximately three times more active than Triton X-100. When the affinity of the bolaphiles toward POPC membranes is considered, the intrinsic membrane-disrupting activity varies by a factor of ca. 230. A "loop" model is proposed to account for the general trends in bolaphile activity that are observed, where the depth of loop penetration and loop width are presumed to be the key factors involved in determining membrane-disrupting activity. The potential utility of these surfactants as antimicrobial agents, and as anti-HIV agents in particular, is briefly discussed.
- Jayasuriya, Nimal,Bosak, Stanislav,Regen, Steven L.
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p. 5844 - 5850
(2007/10/02)
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- A new synthesis of 9,11-dodecadienyl-1-acetate
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Allylation of 9-bromononaldehyde (3) affords the key intermediate hydroxyalkene (4) which on acetylation followed by dehydration gives the title pheromone (1) in quantitative yield.
- Muralikrishna, Chivukala,Dasaradhi, Lakkaraju,Rao, Samala Jagadishwar,Bhalerao, U. T.
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p. 579 - 580
(2007/10/02)
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- Methyl 9-(2-(2,5-Dihydro-5-pentylfuryl))-nonanoate in the Copper-catalyzed Decomposition Products of Methyl Linoleate Hydroperoxide and Some Other Products
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The hydroperoxide of methyl linoleate containing 95 percent 13-hydroperoxide and 5 percent 9-hydroperoxide was decomposed in benzene with 10-4 M cupric naphthenate at 7580 deg C under degassed conditions.The decomposition products were fractionated by Sephadex LH-20 column chromatography with chloroform-hexane (2 : 1, V/V) and the fractions were purified by HPLC.In addition to the known products, three compounds were identified as methyl 9-(2-(2,5-dihydro-5-pentylfuryl))-nonanoate, Methyl 8-(2-furyl)-octanoate, and methyl 9(13)-hydroperoxy-12,13-(9,10)-epoxy-10(12)-octadecenoate as miner decomposition products by MS and IR spectrophotometry.
- Tokita, Masako,Morita, Makio
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p. 309 - 314
(2007/10/02)
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- PHOTOLACTONIZATION: A NOVEL SYNTHETIC ENTRY TO MACROLIDES
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o-Quinol acetates, hydroxyalkylated at C(6), are easily accessible from simple phenols by Wessely acetoxylation (preferentially catalyzed by BF3).On UV irradiation (in the presence of an appropriate tertiary amine), they are smoothly converted to macrocyclic lactones.Subtle conditions have been elaborated to load to high overall yields, and the scope of the conversion of phenols to macrolides has been elucidated.
- Quinkert, Gerhard,Billhardt, Uta-Maria,Jakob, Harald,Fischer, Gerd,Glenneberg, Juergen,et al.
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p. 771 - 821
(2007/10/02)
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- Biosynthetic Studies of Marine Lipids. 5. The Biosynthesis of Long-Chain Branched Fatty Acids in Marine Sponges
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The very long chain branched fatty acids 25-methyl-5,9-hexacosadienoic (Δ5,9-iso-27:2)-and 24-methyl-5,9-hexacosadienoic (Δ5,9-anteiso-27:2) acids as well as the straight-chain 5,9-hexacosadienoic (Δ5,9-26:2) acid were shown to originate from the short-chain precursors 13-methyltetradecanoic (iso-15:0), 12-methyltetradecanoic (anteiso-15:0), and palmitic (n-16:0) acids, respectively, by means of 14C incorporation experiments in the marine sponge Jaspis stellifera.These results confirm that methyl branching does not occur after chain elongation.The unusual Δ5,9 unsaturation probably takes place after chain elongation of short branched or straight-chain fatty acids.
- Carballeira, Nestor,Thompson, Janice E.,Ayanoglu, Eser,Djerassi, Carl
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p. 2751 - 2756
(2007/10/02)
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- An Effective Method for the Preparation of ω-Bromoalkanols from α,ω-Diols
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Pure ω-bromoalkanols 2 (n=2-12), not contaminated by any dibromoalkanes or unreacted diols 1, were prepared in good yields by refluxing a mixture of diols 1, aqueous (48percent) hydrogen bromide, and benzene using a Dean-Stark water separator.
- Kang, Suk-Ku,Kim, Won-Sup,Moon, Byoung-Ho
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p. 1161 - 1162
(2007/10/02)
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- Synthesis and Spectra of Two Novel Catenanes
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In multi-step reaction sequences the precatenanes 23b, c are synthesised.After breaking the chemical bonds between the aromatic nuclei and the bridge head atoms of the double bridged system the -catenanes 25 b, c are obtained.The 13C NMR and mass spectra of the precatenanes and catenanes are discussed.
- Logemann, Enno,Rissler, Klaus,Schill, Gottfried,Fritz, Hans
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p. 2245 - 2260
(2007/10/02)
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