- A simple and cost effective synthesis of 3,11-dimethylnonacosan-2-one, a female sex pheromone of the German cockroach
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A convenient synthesis of 3,11-dimethylnonacosan-2-one (1) is described. Our strategy involves the use of well known C-alkylation and ethyl acetoacetate synthesis reactions as key steps. We expect that this method will prove to be useful for large scale preparation of 1 and modification of dimethylnonacosanones.
- Ahn, Kwang-Chan,Jung, Jae-Chul,Park, Oee-Sook
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- Direct transformation of sterically less hindered silyl ethers to the corresponding bromides with inversion of configuration
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The phosphonium salt 2, generated by adding 2,4,4,6-tetrabromo-2,5-cyclohexadienone1 to triphenylphosphine in CH3CN-THF or 1,2-dichloroethane converted sterically less congested silyl ethers directly to the corresponding bromides in high yields.
- Tanaka, Akira,Oritani, Takayuki
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- Polyunsaturated nitroalkanes and nitro-substituted fatty acids
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Nitroalkanes 4 are readily prepared from naturally derived polyunsaturated fatty alcohols 1 via succesive conversion to the corresponding haloalkanes 2 and 3, and reaction with silver nitrite. Reaction of nitroalkanes 4a,b with methyl acrylate, followed by ester hydrolysis, affords nitro-substituted fatty acids 6a,b and 8a,b. Oxidation of alcohols 1a,b gives the corresponding aldehydes 9a,b, which react by Henry condensation with nitromethane to give β-hydroxynitroalkanes 10a,b.
- Easton,Xia,Pitt,Ferrante,Poulos,Rathjen
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- A mild and efficient method for converting alcohols and tetrahydropyranyl ethers to bromides with inversion of configuration
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Bromotriphenylphosphonium salt 2, generated by adding 2,4,4,6-tetrabromo-2,5-cyclohexamenone (1) to triphenylphosphine in CH2Cl2 or CH2CN converted alcohols and tetrahydropyranyl ethers to the corresponding bromides in high yields.
- Tanaka, Akira,Oritani, Takayuki
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- Synthesis of Phosphonic Acid Ligands for Nanocrystal Surface Functionalization and Solution Processed Memristors
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Here, we synthesized 2-ethylhexyl, 2-hexyldecyl, 2-[2-(2-methoxyethoxy)ethoxy]ethyl, oleyl, and n-octadecyl phosphonic acid and used them to functionalize CdSe and HfO2 nanocrystals. In contrast to branched carboxylic acids, postsynthetic surface functionalization of CdSe and HfO2 nanocrystals was readily achieved with branched phosphonic acids. Phosphonic acid capped HfO2 nanocrystals were subsequently evaluated as memristors using conductive atomic force microscopy. We found that 2-ethylhexyl phosphonic acid is a superior ligand, combining a high colloidal stability with a compact ligand shell that results in a record-low operating voltage that is promising for application in flexible electronics.
- De Roo, Jonathan,Zhou, Zimu,Wang, Jiaying,Deblock, Loren,Crosby, Alfred J.,Owen, Jonathan S.,Nonnenmann, Stephen S.
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p. 8034 - 8039
(2018/10/25)
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- Prenylflavonoids and prenyl/alkyl-phloroacetophenones: Synthesis and antitumour biological evaluation
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Several prenylflavonoids have been synthesised and tested against human tumour cell lines. The prenyl unit has been geranyl or a labdane diterpene. These labdane-flavonoids have been synthesised for the first time. The antitumour activity increase with the prenylation at C-8 position. Twenty-three C and O-prenylated acylphloroglucinols have been synthesised as well. In this case the C-alkylation products have resulted, in general, more active.
- Basabe,De Román,Marcos,Diez,Blanco,Bodero,Mollinedo,Sierra,Urones
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experimental part
p. 4258 - 4269
(2010/10/01)
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- Hypocholesterolemic activity of hesperetin derivatives
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Hesperetin ester and ether derivatives possessing a long alkyl chain were synthesized for examining their hypocholesterolemic activities in high cholesterol-fed mice. Hesperetin 7-O-lauryl ether (4b) and hesperetin 7-O-oleyl ether (4e) exhibited strong cholesterol-lowering effects.
- Jeong, Tae-Sook,Kim, Eun Eai,Lee, Chul-Ho,Oh, Jung-Hoon,Moon, Surk-Sik,Lee, Woo Song,Oh, Goo-Taeg,Lee, Sangku,Bok, Song-Hae
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p. 2663 - 2665
(2007/10/03)
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- Anti-cancer nitro- and thia-fatty acids
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The present invention relates to pharmaceutical compositions comprising, as an anti-cancer agent: (a) one or more compounds having the formula NO2-A-B, wherein A is a saturated or unsaturated hydrocarbon chain of 14-26 double bonds, and B is (CH2)m(COOH)n in which n is a integer from 0 to 2 and m is an integer from 0 to 2; or a derivative thereof in which the hydrocarbon chain has one or more than one substitution selected from the group consisting of hydroxy, hydroperoxy, epoxy and peroxy; (b) one or more compounds selected from polyunsaturated fatty acids (PUFA's) having a 16 to 26 carbon atom chain and 3 to 16 double bonds, and wherein the PUFA is covalently coupled at the carboxylic acid group to an amino acid selected from glycine and aspartic acid; (c) one or more compounds selected from unsaturated fatty acids having an 18 to 25 carbon atom chain and 1 to 6 double bonds and wherein the fatty acid has one or two beta-oxa, gamma-oxa, beta-thia, gamma-thia substitutions: or (d) one or more compounds having formula (I) wherein A' is a saturated or unsaturated hydrocarbon chain of 9-26 carbon atoms, X is oxygen or is absent and B' is (CH2)J(COOH)k in which j is an integer from 1 to 3 and K is 0 or 1; or a derivative thereof in which the hydrocarbon chain has one or more than one substitution selected from the group consisting of hydroxy, hydroperoxy, epoxy and peroxy; and a pharmaceutically acceptable carrier or diluent.
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- Syntheses of long-chain quaternary ammonium salts from fatty alcohols by microwave irradiation
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The phase-transfer catalysts, long-chain quaternary ammonium salts, were rapidly synthesized from fatty alcohols by the reactions with hydrogen halides in the presence of trialkyl amines under microwave irradiation. The catalysts could be widely applied in a variety of quick and new organic reactions, whether by conventional heating or under microwave irradiation. The reaction efficiencies under microwave irradiation were higher than those obtained with conventional heating.
- Jiang,Hu,Pang,Yuan
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p. 847 - 850
(2007/10/03)
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- A New and Efficient One-Pot Preparation of Alkyl Halides From Alcohols
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Primary alkanols and 2-alkenols are converted into the corresponding halides in high yield by a one-pot, two-step reaction via transformation into intermediate trifluoroacetates followed by nucleophilic substitution with lithium halides.
- Camps, Francisco,Gasol, Vicens,Guerrero, Angel
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p. 511 - 512
(2007/10/02)
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- Peptide derivatives
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The present invention relates to new lipopeptides and in particular to compounds of either of the formulae STR1 wherein R1 and R2 each represent a saturated or unsaturated aliphatic or mixed aliphatic-cycloaliphatic hydrocarbon radical which has 11-21 C atoms and which is also optionally substituted by oxygen functions, R3 represents hydrogen or the radical R1 --CO--O--CH2 --, where R1 has the same meaning, R1 ' is a saturated or unsaturated aliphatic hydrocarbon radical of at least 9 C atoms, which is optionally substituted at one of the C atoms non adjacent to the sulfur atom by a free hydroxyl group or a hydroxyl group esterified with a monobasic carboxylic acid and which is optionally interrupted in the C atoms chain by one or more oxygen atoms, and which hydrocarbon is optionally substituted by a maximum of 2 cycloaliphatic hydrocarbon radicals having 5-8 ring C atoms, or R1 ' is the radical --CO--R1 ", wherein R1 " represents a saturated or unsaturated aliphatic or mixed aliphatic-cycloaliphatic hydrocarbon radical of 11-21 C-atoms and which is optionally interrupted in the C atoms chain by oxygen atoms, and X represents an amino acid with free esterified or amidated carboxyl group, or an amino acid sequence of 2-10 aliphatic amino acids, the terminal carboxyl group of which is free or in the ester or amide form, the amino acids being naturals ones in the case of compounds of formula (1).
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- Synthesis of long-chain alkyl and alkenyl bromides.
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Long-chain alkyl and alkenyl bromides are obtained in quantitative yields by the reaction of methane-sulfonates with anhydrous magnesium bromide in absolute ether; cis-trans isomerization of double bonds does not occur.
- Baumann,Mangold
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p. 568 - 569
(2007/10/05)
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