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Tertiary Alcohols (tertiary + alcohol)

Distribution by Scientific Domains

Chemistry	100%

Distribution within Chemistry

Organic Chemistry	52%
General & Introductory Chemistry	33%

Selected Abstracts

ChemInform Abstract: Highly Enantioselective Synthesis of Tertiary Alcohols: C2 -Symmetric N,N,-Dioxide-Sc(III) Complex Promoted Direct Aldol Reaction of ,-Ketoesters and Diazoacetate Esters.

CHEMINFORM, Issue 16 2010
Fei Wang
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Conversion of Tertiary Alcohols to tert-Alkyl Azides by Way of Quinone-Mediated Oxidation,Reduction Condensation Using Alkyl Diphenylphosphinites.

CHEMINFORM, Issue 40 2007
Kiichi Kuroda
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Enantioselective Synthesis of Tertiary Alcohols by the Desymmetrizing Benzoylation of 2-Substituted Glycerols.

CHEMINFORM, Issue 29 2007
Byunghyuck Jung
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

A Novel Reduction Reaction for the Conversion of Aldehydes, Ketones and Primary, Secondary and Tertiary Alcohols into Their Corresponding Alkanes.

CHEMINFORM, Issue 46 2006
Rama D. Nimmagadda
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Copper(II)-Catalyzed O-Phenylation of Tertiary Alcohols with Organobismuth(V) Reagents.

CHEMINFORM, Issue 44 2006
Kazuhiro Ikegai
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Silica Chloride (SiO2,Cl) and Trimethylsilyl Chloride (TMSCl) Promote Facile and Efficient Dehydration of Tertiary Alcohols.

CHEMINFORM, Issue 6 2004
Habib Firouzabadi
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Parameters Influencing the Release of Tertiary Alcohols from the Surface of "Spherical" Dendrimers and "Linear" Stylomers by Neighbouring-Group-Assisted Hydrolysis of 2-Carbamoylbenzoates

CHEMISTRY - A EUROPEAN JOURNAL, Issue 12 2009
Alain Trachsel
Abstract Size is not all! Investigation of the controlled release of tertiary alcohols from the surface of dendrimers and "stylomers" as polymer model systems (see scheme) showed that the polarity of the conjugates and structural modifications in close proximity to the release unit have a stronger influence on the rates of hydrolysis than the size (generation) or shape (linear or spherical) of the macromolecules. The influence of structural and physico-chemical parameters on the release of a volatile tertiary alcohol (2-methyl-1-phenyl-2-propanol) by neighbouring-group-assisted cyclisation of 2-carbamoylbenzoates at neutral pH was investigated by comparing the covalent-bond cleavage from the surface of linear, comblike poly(propylene imine) "stylomers" and their corresponding spherical, globular dendrimers. Determination of the kinetic rate constants for the stepwise intramolecular cyclisation of the 2-carbamoylbenzoate moiety by using HPLC showed that the polarity of the conjugates, and thus their solubility in the aqueous reaction medium, has a stronger influence on the rates of hydrolysis than the size (generation) or shape (linear or spherical) of the macromolecules. Furthermore, structural modifications in close proximity to the release unit, such as the presence of functionalities with catalytic activity, have a strong impact on the release efficiency of the active molecules. An understanding of the physico-chemical parameters determining the local environment of the covalent-bond cleavage site is therefore an important prerequisite to transfer the characteristics of small molecules to larger structures such as oligomers and polymers and thus to design efficient macromolecular conjugates for the controlled delivery of bioactive compounds. L'influence des paramètres structurels et physico-chimiques sur le relargage à pH neutre d'un alcool tertiaire volatil (2-méthyl-1-phényl-2-propanol) par cyclisation de 2-carbamoylbenzoates assistée par un groupe voisin a été étudiée. Les ruptures de liaisons covalentes depuis la surface de poly(propylene imines) en forme de peigne ("stylomères") d'une part et de leurs analogues sphériques et globulaires (dendrimères) correspondants d'autre part ont été comparées. La détermination par CLHP des constantes cinétiques pour la cyclisation intramoléculaire des unités 2-carbamoylbenzoate par étapes a montré que la polarité des conjugués, et par conséquent leur solubilité dans le milieu de réaction aqueux, a une influence plus forte sur les vitesses d'hydrolyse que la taille (génération) ou la forme (linéaire ou sphérique) des macromolécules. De plus, des modifications structurelles à proximité immédiate de l'unité de relargage telles que la présence de groupes fonctionnels avec une activité catalytique ont un fort impact sur l'efficacité de relargage des molécules actives. La compréhension des paramètres physico-chimiques qui déterminent l'environnement local du site de rupture de la liaison covalente est par conséquent une condition préalable importante lors du transfert de caractéristiques de petites molécules à des structures plus grandes telles que des oligomères et des polymères, et donc à la conception de conjugués macromoléculaires efficaces pour le relargage contrôlé de composés bioactifs. [source]

Novel Cyclic 1,2-Diacetals Derived from (2R,3R)-(+)-Tartaric Acid: Synthesis and Application as N,O Ligands for the Enantioselective Alkylation of Benzaldehyde by Diethylzinc

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2004
M. Teresa Barros
Abstract A chiral cyclic 1,2-diacetal derived from tartaric acid was used as the basic structural unit for novel ligands. Monooxazoline carbinols in which the degree of substitution of the alcohol and the nature of the stereocentre in the oxazoline ring were varied were synthesized in moderate to good yields. The influence of these structural factors on asymmetric induction was examined in the enantioselective addition of diethylzinc to benzaldehyde. Up to 60% ee was observed with a secondary or a tertiary alcohol as the metal-chelating group. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

A Novel Proline-Valinol Thioamide Small Organic Molecule for a Highly Enantioselective Direct Aldol Reaction

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009
Bing Wang
Abstract A new prolinethioamide compound 4, prepared from readily available natural amino acid L -proline and amino alcohol L -valinol, has been found to be an active catalyst for the direct aldol reaction of various aldehydes with acetone, cyclohexanone or cyclopentanone at 0,°C. Using only 2,mol% loading of this organocatalyst, the reaction could give high enantioselectivity with up to 96% enantiomeric excess for the reaction of 2-nitrobenzaldehyde with acetone. And as for the cyclohexanone, the excellent diastereoselectivity (anti/syn: 99/1) and enantioselectivity (99% ee) could be achieved when reacted with 3-nitrobenzaldehyde in water in the presence of this thioamide 4. This structurally simple catalyst is a highly efficient prolinethioamide derivative, and the terminal hydroxy group in this catalyst is a primary alcohol which is different from the previously reported prerequisite secondary or tertiary alcohol of prolinamides. Our results suggest a new strategy in the design of diversiform organic catalysts for direct asymmetric aldol reactions and related transformations. [source]

Physico-enzymatic production of monoacylglycerols enriched with very-long-chain polyunsaturated fatty acids

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2008
Ratchapol Pawongrat
Abstract BACKGROUND: Monoacylglycerols (MAG) containing polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have interesting applications. The enzymatic processing of such MAG directly from fish oils is highly interesting, integrating the processing of MAG and concentration of EPA and DHA. The aim of this study was to develop an efficient enzymatic glycerolysis system together with physical fractionation for the production of PUFA-MAG from tuna oil. RESULTS: Novozym 435 was eventually selected after evaluation together with immobilized lipase AK in a tertiary alcohol-based system. A further evaluation of solvent mixtures involving tertiary alcohols was made, taking ease of operation into consideration. It turned out that a number of mixtures gave a similar performance to that of tert -butanol (TB). Basic reaction parameters were thoroughly evaluated. In the batch reaction system with TB as solvent, the recommended conditions were: glycerol/tuna oil 4:1 (mol/mol), TB/tuna oil 2:1 (wt/wt), 15 wt% Novozym 435, and temperature 40 °C. Under these conditions, the yield of MAG was up to 90% after 3 h incubation. Crude MAG from the production was fractionated to produce MAG with higher EPA and DHA content. Using acetone as solvent at 0 °C led to ca 50% yield of MAG but contained EPA and DHA up to 71% in comparison with ca 30% in tuna oil. CONCLUSION: Potentially practical process steps have been developed for the production of MAG containing a high content of EPA and DHA from natural fish oils with high efficiency and simplicity. Copyright © 2007 Society of Chemical Industry [source]

Parameters Influencing the Release of Tertiary Alcohols from the Surface of "Spherical" Dendrimers and "Linear" Stylomers by Neighbouring-Group-Assisted Hydrolysis of 2-Carbamoylbenzoates

A New Neighbouring-Group Reaction to Form Pyridopyrrolobenzoxazinediones

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2004
Gerhard Hamprecht
Abstract The azaphthalimide 2a is the first phthalimide oxygen found to undergo a neighboring-group participation reaction with a vicinal N -phenyl carboxylic acid chloride upon nucleophilic addition with alcohols. Owing to the free rotation of the N -phenyl moiety, hetero-anellated benzoxazinedione isomers 3 and 4 are accessible, whereby 3 is preferred to 4 as the pyridine nitrogen in 2a preferentially activates the o -carbonyl group. Yields of up to 92% were obtained when bases such as HCl acceptors were avoided by heating 2a with alcohols. The reaction is restricted to primary and secondary alcohols, as 2a is nonplanar in respect of the heterocyclic and benzene moiety, which prevents tertiary alcohols attacking the pyrrolidinedione carbonyl group. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Overcrowded 5,10,15-Trisubstituted Derivatives: Synthesis of 5,10,15-Tri(fluorenylidene)truxene

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2004
Marta Ruiz
Abstract Sterically crowded 5,10,15-triarylated truxenes are obtained by reaction of truxenetrione with aryllithium compounds (aryl = 1-naphthyl, 2-naphthyl, 9-phenanthryl, 9-anthracenyl), followed by reduction of the tertiary alcohols with Et3SiH and BF3. Base-catalyzed isomerization of the anti derivatives provides syn -5,10,15-triarylated derivatives, with the exception of the 9-anthracenyl that could not be isomerized. Overcrowded 5,10,15-tri(fluorenylidene)truxene was also synthesized starting form the addition of fluorenyllithium to truxenetrione. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Controlled Release of Perfumery Alcohols by Neighboring-Group Participation.

HELVETICA CHIMICA ACTA, Issue 8 2003
2-(Hydroxymethyl)-, 2-Carbamoylbenzoates, Comparison of the Rate Constants for the Alkaline Hydrolysis of 2-Acyl-
A series of 2-acylbenzoates 1 and 2, 2-(hydroxymethyl)benzoates 3, 2-carbamoylbenzoates 4,6, as well as the carbamoyl esters 7 or 8 of maleate or succinate, respectively (see Fig.,2), were prepared in a few reaction steps, and the potential use of these compounds as chemical delivery systems for the controlled release of primary, secondary, and tertiary fragrance alcohols was investigated. The rate constants for the neighboring-group-assisted alkaline ester hydrolysis were determined by anal. HPLC in buffered H2O/MeCN solution at different pH (Table,1). The rates of hydrolysis were found to depend on the structure of the alcohol, together with the precursor skeleton and the structure of the neighboring nucleophile that attacks the ester function. Primary alcohols were released more rapidly than secondary and tertiary alcohols, and benzoates of allylic primary alcohols (e.g., geraniol) were hydrolyzed 2,4 times faster than their homologous saturated alcohols (e.g., citronellol). For the same leaving alcohol, 2-[(ethylamino)carbonyl]benzoates cyclized faster than the corresponding 2-(hydroxymethyl)benzoates, and much faster than their 2-formyl and 2-acetyl analogues (see, e.g., Fig.,4). Within the carbamoyl ester series, 2-[(ethylamino)carbonyl]benzoates were found to have the highest rate constants for the alkaline ester hydrolysis, followed by unsubstituted 2-(aminocarbonyl)benzoates, or the corresponding isopropyl derivatives. To rationalize the influence of the different structural changes on the hydrolysis kinetics, the experimental data obtained for the 2-[(alkylamino)carbonyl]benzoates were compared with the results of density-functional computer simulations (Table,2 and Scheme,4). Based on a preliminary semi-empirical conformation analysis, density-functional calculations at the B3LYP/6-31G** level were carried out for the starting precursor molecules, several reaction intermediates, and the cyclized phthalimides. For the same precursor skeleton, these simple calculations were found to model the experimental data correctly. With an understanding of the influence of structural parameters on the rate constants obtained in this work, it is now possible to influence the rates of hydrolysis over several orders of magnitude, to design tailor-made precursors for a large variety of fragrance alcohols, and to predict their efficiency as controlled-release systems in practical applications. [source]

Substitution- and Elimination-Free Phosphorylation of Functionalized Alcohols Catalyzed by Oxidomolybdenum Tetrachloride

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010
Cheng-Yuan Liu
Abstract Among 14 oxidometallic species examined for catalytic phosphorylation of the tested alcohols, oxidomolybdenum tetrachloride (MoOCl4) was found to be the most efficient with a negligible background reaction mediated by triethylamine (Et3N). The new catalytic protocol can be applied to the chemoselective phosphorylations of primary, secondary and tertiary alcohols as well as the substitution-free phosphorylations of allylic, propargylic, and benzylic alcohols. Functionalized alcohols bearing acetonide, tetrahydropyranyl ether, tert -butyldimethylsilyl ether, or ester group are also amenable to the new catalytic protocol. The most difficult scenarios involve substitution-free phosphorylations of 1-phenylethanol and 1-(2-naphthyl)ethanol which can be effected in 95 and 90% yields, respectively. ESI-MS, IR, 1H, and 31P,NMR spectroscopic analyses of the reaction progress suggest the intermediacy of an alkoxyoxidomolybdenum trichloride-triethylamine adduct such as [(RO)Mo(O)Cl3 -Et3N] to be responsible for the catalytic turnover. [source]

Physico-enzymatic production of monoacylglycerols enriched with very-long-chain polyunsaturated fatty acids

Rapid, highly efficient and chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by reusable electron-deficient tin(IV)porphyrin

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2009
Majid Moghadam
Abstract In this paper, rapid and highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) in the presence of catalytic amounts of high-valent [SnIV(TPP)(OTf)2] is reported. This catalytic system catalyzes trimethylsilylation of primary, secondary and tertiary alcohols as well as phenols, and the corresponding TMS-ethers were obtained in high yields and short reaction times at room temperature. It is noteworthy that this method can be used for chemoselective silylation of primary alcohols in the presence of secondary and tertiary alcohols and phenols. The catalyst was reused several times without loss of its catalytic activity. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Parameters Influencing the Release of Tertiary Alcohols from the Surface of "Spherical" Dendrimers and "Linear" Stylomers by Neighbouring-Group-Assisted Hydrolysis of 2-Carbamoylbenzoates

Discovery of New Biocatalysts for the Glycosylation of Terpenoid Scaffolds

CHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2008
Lorenzo Caputi
Abstract The synthesis of terpenoid glycosides typically uses a chemical strategy since few biocatalysts have been identified that recognise these scaffolds. In this study, a platform of 107 recombinant glycosyltransferases (GTs), comprising the multigene family of small molecule GTs of Arabidopsis thaliana have been screened against a range of model terpenoid acceptors to identify those enzymes with high activity. Twenty-seven GTs are shown to glycosylate a diversity of mono-, sesqui- and diterpenes, such as geraniol, perillyl alcohol, artemisinic acid and retinoic acid. Certain enzymes showing substantial sequence similarity recognise terpenoids containing a primary alcohol, irrespective of the linear or cyclical structure of the scaffold; other GTs glycosylate scaffolds containing secondary and tertiary alcohols; the carboxyl group of other terpenoids also represents a feature that is recognized by GTs previously known to form glucose esters with many different compounds. These data underpin the rapid prediction of potential biocatalysts from GT sequence information. To explore the potential of GTs as biocatalysts, their use for the production of terpenoid glycosides was investigated by using a microbial-based whole-cell biotransformation system capable of regenerating the cofactor, UDP-glucose. A high cell density fermentation system was shown to produce several hundred milligrams of a model terpenoid, geranyl-glucoside. The activities of the GTs are discussed in relation to their substrate recognition and their utility in biotransformations as a complement or alternative to chemical synthesis. [source]

Water Compatible Gold(III)-Catalysed Synthesis of Unsymmetrical Ethers from Alcohols

CHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2008

Abstract An efficient and broad-scoped method for the preparation of unsymmetrical ethers from alcohols catalysed by the simplest and least expensive gold catalyst, NaAuCl4, is described for the first time. The procedure enables the etherification of benzylic and tertiary alcohols with moderate to good yields under mild conditions with low catalyst loading. Symmetrical ethers, the usual side products in the etherification of alcohols, were not detected in this case. The formation of the racemic ether from a chiral benzyl alcohol suggests the intermediacy of a carbocation, which has not previously been postulated for gold-catalysed reactions involving alcohols. [source]

Straightforward Synthesis of (R)-(,)-Kjellmanianone

CHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2004
Jens Christoffers Prof. Dr.
Abstract A direct route to enantiomerically pure (,)-kjellmanianone is reported. The synthesis involves a cerium-catalyzed ,-hydroxylation and an enzyme-catalyzed procedure to resolve tertiary alcohols at key stages. The intermediate ,-oxo ester was ,-hydroxylated to give good yields of racemic kjellmanianone. The resolution of the racemic material was achieved by enzymatic saponification, followed by a chemical decarboxylation sequence to give enantiopure (,)-kjellmanianone with 99,% ee. Bromination then afforded the (,)-bromo derivative, whose X-ray structure provided evidence for the R configuration of (,)-kjellmanianone. [source]