In chemistry, an ester is a functional group derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidichydroxyl group (−OH) of that acid is replaced by an organyl group (R′). Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well.[1] According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides), but not according to the IUPAC.[1]
Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Lactones are cyclic carboxylic esters; naturally occurring lactones are mainly 5- and 6-membered ring lactones. Lactones contribute to the aroma of fruits, butter, cheese, vegetables like celery and other foods.
There are compounds in which an acidic hydrogen of acids mentioned in this article are not replaced by an organyl, but by some other group. According to some authors, those compounds are esters as well, especially when the first carbon atom of the organyl group replacing acidic hydrogen, is replaced by another atom from the group 14 elements (Si, Ge, Sn, Pb); for example, according to them, trimethylstannyl acetate (or trimethyltin acetate) CH3COOSn(CH3)3 is a trimethylstannyl ester of acetic acid, and dibutyltin dilaurate(CH3(CH2)10COO)2Sn((CH2)3CH3)2 is a dibutylstannylene ester of lauric acid, and the Phillips catalystCrO2(OSi(OCH3)3)2 is a trimethoxysilyl ester of chromic acid (H2CrO4).[4][5]
Nomenclature
Etymology
The word ester was coined in 1848 by a German chemist Leopold Gmelin,[6] probably as a contraction of the German Essigäther, "acetic ether".
The names of esters that are formed from an alcohol and an acid, are derived from the parent alcohol and the parent acid, where the latter may be organic or inorganic. Esters derived from the simplest carboxylic acids are commonly named according to the more traditional, so-called "trivial names" e.g. as formate, acetate, propionate, and butyrate, as opposed to the IUPAC nomenclature methanoate, ethanoate, propanoate, and butanoate. Esters derived from more complex carboxylic acids are, on the other hand, more frequently named using the systematic IUPAC name, based on the name for the acid followed by the suffix -oate. For example, the ester hexyl octanoate, also known under the trivial name hexyl caprylate, has the formula CH3(CH2)6CO2(CH2)5CH3.
The chemical formulas of organic esters formed from carboxylic acids and alcohols usually take the form RCO2R' or RCOOR', where R and R' are the organyl parts of the carboxylic acid and the alcohol, respectively, and R can be a hydrogen in the case of esters of formic acid. For example, butyl acetate (systematically butyl ethanoate), derived from butanol and acetic acid (systematically ethanoic acid) would be written CH3CO2(CH2)3CH3. Alternative presentations are common including BuOAc and CH3COO(CH2)3CH3.
Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.
Orthoesters
An uncommon class of esters are the orthoesters. One of them are the esters of orthocarboxylic acids. Those esters have the formula RC(OR′)3, where R stands for any group (organic or inorganic) and R′ stands for organyl group. For example, triethyl orthoformate (HC(OCH2CH3)3) is derived, in terms of its name (but not its synthesis) from esterification of orthoformic acid (HC(OH)3) with ethanol.
Inorganic acids that exist as tautomers form two or more types of esters.
Thiosulfuric acid forms two types of thiosulfate esters, e.g. O,O-dimethyl thiosulfate ((CH3−O−)2S(=O)(=S)) and O,S-dimethyl thiosulfate ((CH3−O−)(CH3−S−)S(=O)2)
Esters derived from carboxylic acids and alcohols contain a carbonyl group C=O, which is a divalent group at C atom, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, carboxylic acid esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides.[7] The pKa of the alpha-hydrogens on esters of carboxylic acids is around 25 (alpha-hydrogen is a hydrogen bound to the carbon adjacent to the carbonyl group (C=O) of carboxylate esters).[8]
Many carboxylic acid esters have the potential for conformational isomerism, but they tend to adopt an S-cis (or Z) conformation rather than the S-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present.[9][10]Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.
Physical properties and characterization
Esters derived from carboxylic acids and alcohols are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.[7]
Characterization and analysis
Esters are generally identified by gas chromatography, taking advantage of their volatility. IR spectra for esters feature an intense sharp band in the range 1730–1750 cm−1 assigned to νC=O. This peak changes depending on the functional groups attached to the carbonyl. For example, a benzene ring or double bond in conjunction with the carbonyl will bring the wavenumber down about 30 cm−1.
Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials, and often have a pleasant characteristic, fruity odor. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers.
Esterification of carboxylic acids with alcohols
The classic synthesis is the Fischer esterification, which involves treating a carboxylic acid with an alcohol in the presence of a dehydrating agent:
RCO2H + R'OH ⇌ RCO2R' + H2O
The equilibrium constant for such reactions is about 5 for typical esters, e.g., ethyl acetate.[15] The reaction is slow in the absence of a catalyst. Sulfuric acid is a typical catalyst for this reaction. Many other acids are also used such as polymeric sulfonic acids. Since esterification is highly reversible, the yield of the ester can be improved using Le Chatelier's principle:
Using the alcohol in large excess (i.e., as a solvent).
Using a dehydrating agent: sulfuric acid not only catalyzes the reaction but sequesters water (a reaction product). Other drying agents such as molecular sieves are also effective.
Reagents are known that drive the dehydration of mixtures of alcohols and carboxylic acids. One example is the Steglich esterification, which is a method of forming esters under mild conditions. The method is popular in peptide synthesis, where the substrates are sensitive to harsh conditions like high heat. DCC (dicyclohexylcarbodiimide) is used to activate the carboxylic acid to further reaction. 4-Dimethylaminopyridine (DMAP) is used as an acyl-transfer catalyst.[16]
Another method for the dehydration of mixtures of alcohols and carboxylic acids is the Mitsunobu reaction:
Carboxylic acids can be esterified using diazomethane:
RCO2H + CH2N2 → RCO2CH3 + N2
Using this diazomethane, mixtures of carboxylic acids can be converted to their methyl esters in near quantitative yields, e.g., for analysis by gas chromatography. The method is useful in specialized organic synthetic operations but is considered too hazardous and expensive for large-scale applications.
Esterification of carboxylic acids with epoxides
Carboxylic acids are esterified by treatment with epoxides, giving β-hydroxyesters:
The reactions are irreversible simplifying work-up. Since acyl chlorides and acid anhydrides also react with water, anhydrous conditions are preferred. The analogous acylations of amines to give amides are less sensitive because amines are stronger nucleophiles and react more rapidly than does water. This method is employed only for laboratory-scale procedures, as it is expensive.
Although rarely employed for esterifications, carboxylate salts (often generated in situ) react with electrophilicalkylating agents, such as alkyl halides, to give esters.[14][18] Anion availability can inhibit this reaction, which correspondingly benefits from phase transfer catalysts or such highly polar aprotic solvents as DMF. An additional iodide salt may, via the Finkelstein reaction, catalyze the reaction of a recalcitrant alkyl halide. Alternatively, salts of a coordinating metal, such as silver, may improve the reaction rate by easing halide elimination.
Transesterification
Transesterification, which involves changing one ester into another one, is widely practiced:
RCO2R' + CH3OH → RCO2CH3 + R'OH
Like the hydrolysation, transesterification is catalysed by acids and bases. The reaction is widely used for degrading triglycerides, e.g. in the production of fatty acid esters and alcohols. Poly(ethylene terephthalate) is produced by the transesterification of dimethyl terephthalate and ethylene glycol:[14]
n (C6H4)(CO2CH3)2 + 2n C2H4(OH)2 → [(C6H4)(CO2)2(C2H4)]n + 2n CH3OH
A subset of transesterification is the alcoholysis of diketene. This reaction affords 2-ketoesters.[14]
Esters are less reactive than acid halides and anhydrides. As with more reactive acyl derivatives, they can react with ammonia and primary and secondary amines to give amides, although this type of reaction is not often used, since acid halides give better yields.
Transesterification
Esters can be converted to other esters in a process known as transesterification. Transesterification can be either acid- or base-catalyzed, and involves the reaction of an ester with an alcohol. Unfortunately, because the leaving group is also an alcohol, the forward and reverse reactions will often occur at similar rates. Using a large excess of the reactant alcohol or removing the leaving group alcohol (e.g. via distillation) will drive the forward reaction towards completion, in accordance with Le Chatelier's principle.[24]
Acid-catalyzed hydrolysis of esters is also an equilibrium process – essentially the reverse of the Fischer esterification reaction. Because an alcohol (which acts as the leaving group) and water (which acts as the nucleophile) have similar pKa values, the forward and reverse reactions compete with each other. As in transesterification, using a large excess of reactant (water) or removing one of the products (the alcohol) can promote the forward reaction.
Basic hydrolysis of esters, known as saponification, is not an equilibrium process; a full equivalent of base is consumed in the reaction, which produces one equivalent of alcohol and one equivalent of a carboxylate salt. The saponification of esters of fatty acids is an industrially important process, used in the production of soap.[24]
Esterification is a reversible reaction. Esters undergo hydrolysis under acidic and basic conditions. Under acidic conditions, the reaction is the reverse reaction of the Fischer esterification. Under basic conditions, hydroxide acts as a nucleophile, while an alkoxide is the leaving group. This reaction, saponification, is the basis of soap making.
The alkoxide group may also be displaced by stronger nucleophiles such as ammonia or primary or secondary amines to give amides (ammonolysis reaction):
RCO2R' + NH2R″ → RCONHR″ + R'OH
This reaction is not usually reversible. Hydrazines and hydroxylamine can be used in place of amines. Esters can be converted to isocyanates through intermediate hydroxamic acids in the Lossen rearrangement.
Sources of carbon nucleophiles, e.g., Grignard reagents and organolithium compounds, add readily to the carbonyl.
Reduction
Compared to ketones and aldehydes, esters are relatively resistant to reduction. The introduction of catalytic hydrogenation in the early part of the 20th century was a breakthrough; esters of fatty acids are hydrogenated to fatty alcohols.
RCO2R' + 2 H2 → RCH2OH + R'OH
A typical catalyst is copper chromite. Prior to the development of catalytic hydrogenation, esters were reduced on a large scale using the Bouveault–Blanc reduction. This method, which is largely obsolete, uses sodium in the presence of proton sources.
Especially for fine chemical syntheses, lithium aluminium hydride is used to reduce esters to two primary alcohols. The related reagent sodium borohydride is slow in this reaction. DIBAH reduces esters to aldehydes.[25]
Direct reduction to give the corresponding ether is difficult as the intermediate hemiacetal tends to decompose to give an alcohol and an aldehyde (which is rapidly reduced to give a second alcohol). The reaction can be achieved using triethylsilane with a variety of Lewis acids.[26][27]
Claisen condensation and related reactions
Esters can undergo a variety of reactions with carbon nucleophiles. They react with an excess of a Grignard reagent to give tertiary alcohols. Esters also react readily with enolates. In the Claisen condensation, an enolate of one ester (1) will attack the carbonyl group of another ester (2) to give tetrahedral intermediate 3. The intermediate collapses, forcing out an alkoxide (R'O−) and producing β-keto ester 4.
Crossed Claisen condensations, in which the enolate and nucleophile are different esters, are also possible. An intramolecular Claisen condensation is called a Dieckmann condensation or Dieckmann cyclization, since it can be used to form rings. Esters can also undergo condensations with ketone and aldehyde enolates to give β-dicarbonyl compounds.[28] A specific example of this is the Baker–Venkataraman rearrangement, in which an aromatic ortho-acyloxy ketone undergoes an intramolecular nucleophilic acyl substitution and subsequent rearrangement to form an aromatic β-diketone.[29] The Chan rearrangement is another example of a rearrangement resulting from an intramolecular nucleophilic acyl substitution reaction.
Esters react with nucleophiles at the carbonyl carbon. The carbonyl is weakly electrophilic but is attacked by strong nucleophiles (amines, alkoxides, hydride sources, organolithium compounds, etc.). The C–H bonds adjacent to the carbonyl are weakly acidic but undergo deprotonation with strong bases. This process is the one that usually initiates condensation reactions. The carbonyl oxygen in esters is weakly basic, less so than the carbonyl oxygen in amides due to resonance donation of an electron pair from nitrogen in amides, but forms adducts.
As for aldehydes, the hydrogen atoms on the carbon adjacent ("α to") the carboxyl group in esters are sufficiently acidic to undergo deprotonation, which in turn leads to a variety of useful reactions. Deprotonation requires relatively strong bases, such as alkoxides. Deprotonation gives a nucleophilic enolate, which can further react, e.g., the Claisen condensation and its intramolecular equivalent, the Dieckmann condensation. This conversion is exploited in the malonic ester synthesis, wherein the diester of malonic acid reacts with an electrophile (e.g., alkyl halide), and is subsequently decarboxylated. Another variation is the Fráter–Seebach alkylation.
As a class, esters serve as protecting groups for carboxylic acids. Protecting a carboxylic acid is useful in peptide synthesis, to prevent self-reactions of the bifunctional amino acids. Methyl and ethyl esters are commonly available for many amino acids; the t-butyl ester tends to be more expensive. However, t-butyl esters are particularly useful because, under strongly acidic conditions, the t-butyl esters undergo elimination to give the carboxylic acid and isobutylene, simplifying work-up.
Many esters have distinctive fruit-like odors, and many occur naturally in the essential oils of plants. This has also led to their common use in artificial flavorings and fragrances which aim to mimic those odors.
Depside, a polymeric ester, a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester group
Depsipeptide, a type of ester that is a peptide in which one or more of its amide groups (−C(=O)−NH−) are replaced by the corresponding ester groups (−C(=O)−O−)[31]
^Leopold Gmelin, Handbuch der Chemie, vol. 4: Handbuch der organischen Chemie (vol. 1) (Heidelberg, Baden (Germany): Karl Winter, 1848), page 182.
Original text:
b. Ester oder sauerstoffsäure Aetherarten. Ethers du troisième genre.
Viele mineralische und organische Sauerstoffsäuren treten mit einer Alkohol-Art unter Ausscheidung von Wasser zu neutralen flüchtigen ätherischen Verbindungen zusammen, welche man als gepaarte Verbindungen von Alkohol und Säuren-Wasser oder, nach der Radicaltheorie, als Salze betrachten kann, in welchen eine Säure mit einem Aether verbunden ist.
Translation:
b. Ester or oxy-acid ethers. Ethers of the third type.
Many mineral and organic acids containing oxygen combine with an alcohol upon elimination of water to [form] neutral, volatile ether compounds, which one can view as coupled compounds of alcohol and acid-water, or, according to the theory of radicals, as salts in which an acid is bonded with an ether.
^ abMarch, J. Advanced Organic Chemistry 4th Ed. J. Wiley and Sons, 1992: New York. ISBN0-471-60180-2.
^Diwakar M. Pawar; Abdelnaser A. Khalil; Denise R. Hooks; Kenneth Collins; Tijuana Elliott; Jefforey Stafford; Lucille Smith; Eric A. Noe (1998). "E and Z Conformations of Esters, Thiol Esters, and Amides". Journal of the American Chemical Society. 120 (9): 2108–2112. doi:10.1021/ja9723848.
^Christophe Dugave; Luc Demange (2003). "Cis−Trans Isomerization of Organic Molecules and Biomolecules: Implications and Applications". Chemical Reviews. 103 (7): 2475–2932. doi:10.1021/cr0104375. PMID12848578.
^A. A. Yakovenko; J. H. Gallegos; M. Yu. Antipin; A. Masunov; T. V. Timofeeva (2011). "Crystal Morphology as an Evidence of Supramolecular Organization in Adducts of 1,2-Bis(chloromercurio)tetrafluorobenzene with Organic Esters". Crystal Growth & Design. 11 (9): 3964–3978. doi:10.1021/cg200547k.
^Isolation of triglyceride from nutmeg: G. D. Beal "Trimyristen" Organic Syntheses, Coll. Vol. 1, p.538 (1941). Link
^McGee, Harold. On Food and Cooking. 2003, Scribner, New York.
^Williams, Roger J.; Gabriel, Alton; Andrews, Roy C. (1928). "The Relation Between the Hydrolysis Equilibrium Constant of Esters and the Strengths of the Corresponding Acids". Journal of the American Chemical Society. 50 (5): 1267–1271. doi:10.1021/ja01392a005.
^Raber, Douglas J.; Gariano, Jr, Patrick; Brod, Albert O.; Gariano, Anne L.; Guida, Wayne C. (1977). "Esterification of Carboxylic Acids with Trialkyloxonium Salts: Ethyl and Methyl 4-Acetoxybenzoates". Organic Syntheses. 56: 59. doi:10.15227/orgsyn.056.0059.
^Neumeister, Joachim; Keul, Helmut; Pratap Saxena, Mahendra; Griesbaum, Karl (1978). "Ozone Cleavage of Olefins with Formation of Ester Fragments". Angewandte Chemie International Edition in English. 17 (12): 939–940. doi:10.1002/anie.197809392.
^Makhova, Irina V.; Elinson, Michail N.; Nikishin, Gennady I. (1991). "Electrochemical oxidation of ketones in methanol in the presence of alkali metal bromides". Tetrahedron. 47 (4–5): 895–905. doi:10.1016/S0040-4020(01)87078-2.
^Yato, Michihisa; Homma, Koichi; Ishida, Akihiko (June 2001). "Reduction of carboxylic esters to ethers with triethyl silane in the combined use of titanium tetrachloride and trimethylsilyl trifluoromethanesulfonate". Tetrahedron. 57 (25): 5353–5359. doi:10.1016/S0040-4020(01)00420-3.
^Sakai, Norio; Moriya, Toshimitsu; Konakahara, Takeo (July 2007). "An Efficient One-Pot Synthesis of Unsymmetrical Ethers: A Directly Reductive Deoxygenation of Esters Using an InBr3/Et3SiH Catalytic System". The Journal of Organic Chemistry. 72 (15): 5920–5922. doi:10.1021/jo070814z. PMID17602594.
^Wood, J. L.; Khatri, N. A.; Weinreb, S. M. (1979). "A direct conversion of esters to nitriles". Tetrahedron Letters. 20 (51): 4907. doi:10.1016/S0040-4039(01)86746-0.
Association football club in England Football clubAFC WhyteleafeFull nameAFC WhyteleafeNickname(s)'LeafeFounded2021GroundChurch Road, WhyteleafeCapacity2,000ChairmanKelly WatersManagerKelly WatersLeagueSouthern Counties East League Division One2022–23Southern Counties East League Division One, 8th of 17WebsiteClub website Home colours AFC Whyteleafe is an English football club based in Whyteleafe, Surrey. The club was established in 2021 and plays at the Whyteleafe Stadium in Church Road, Whyt…
Juan José Domenchina Información personalNacimiento 18 de mayo de 1898 Madrid (España) Fallecimiento 27 de octubre de 1959 (61 años)Ciudad de México (México) Sepultura Panteón EspañolNacionalidad EspañolaFamiliaCónyuge Ernestina de Champourcín Información profesionalOcupación Escritor y poeta Género Poesía Partido político Izquierda Republicana [editar datos en Wikidata] Juan José Domenchina Moreu (Madrid, 18 de mayo de 1898 - México, 27 de octubre de 1959) fue un esc…
Questa voce o sezione sull'argomento attori britannici non cita le fonti necessarie o quelle presenti sono insufficienti. Puoi migliorare questa voce aggiungendo citazioni da fonti attendibili secondo le linee guida sull'uso delle fonti. Segui i suggerimenti del progetto di riferimento. Simon Pegg nel 2016 Simon Pegg, all'anagrafe Simon John Beckingham (Brockworth, 14 febbraio 1970), è un attore, comico e sceneggiatore britannico. Indice 1 Biografia 2 Vita privata 3 Filmografia 3.1 Attore …
American basketball player and coach (born 1963) Jeff HornacekHornacek in March 2013Utah JazzPositionCoaching consultantLeagueNBAPersonal informationBorn (1963-05-03) May 3, 1963 (age 61)Elmhurst, Illinois, U.S.Listed height6 ft 4 in (1.93 m)Listed weight190 lb (86 kg)Career informationHigh schoolLyons Township (La Grange, Illinois)CollegeIowa State (1982–1986)NBA draft1986: 2nd round, 46th overall pickSelected by the Phoenix SunsPlaying career1986–2000PositionS…
Cet article est une ébauche concernant une localité italienne et le Latium. Vous pouvez partager vos connaissances en l’améliorant (comment ?) selon les recommandations des projets correspondants. Roccantica Administration Pays Italie Région Latium Province Rieti Code postal 02040 Code ISTAT 057061 Code cadastral H427 Préfixe tel. 0765 Démographie Gentilé roccolani Population 550 hab. (31-05-2018[1]) Densité 34 hab./km2 Géographie Coordonnées 42° 19…
English footballer Tom Sang Sang with Port Vale in 2023Personal informationFull name Thomas Roy Sang[1]Date of birth (1999-06-29) 29 June 1999 (age 24)[2]Place of birth Liverpool, England[2]Height 6 ft 2 in (1.88 m)[2]Position(s) Defensive midfielder; right-backTeam informationCurrent team Port ValeNumber 4Youth career2011–2013 Bolton Wanderers2015–2018 Manchester UnitedSenior career*Years Team Apps (Gls)2018–2019 Manchester United 0 (0)2…
DC-10 Air Tanker Tanker 910 fighting the Rim Fire, August 2013 Role Aerial firefightingType of aircraft Manufacturer McDonnell Douglas (conversion by 10 Tanker STC) First flight 2006 Introduction 2006 Primary user 10 Tanker Air Carrier Number built 5 converted from former airliners Developed from McDonnell Douglas DC-10 The DC-10 Air Tanker is a series of American wide-body jet air tankers, which have been in service as an aerial firefighting unit since 2006.[1] The aircraft, operat…
14.º Ejército VVS i PVO 14-я армия ВВС и ПВО Activa 1 de junio de 1998País . RusiaFidelidad Ministerio de Defensa de RusiaFuerzas Armadas de RusiaRama/s Fuerzas Aeroespaciales (VKS)Tipo Fuerza AéreaDefensa aéreaFunción Defensa y ControlParte de Distrito Militar CentroAcuartelamiento EkaterimburgoDisolución 1 de diciembre de 2009Alto mandoComandante Teniente generalAlexander Yuryevich Tatarenko sin etiquetar y sin etiquetar ←Actual [editar datos en Wikidata] El 14.…
الجبهة الديمقراطية لتحرير فلسطين البلد دولة فلسطين التأسيس تاريخ التأسيس 1969 المؤسسون نايف حواتمة الشخصيات قائد الحزب نايف حواتمة القادة نايف حواتمة (أمين عام) الأفكار الأيديولوجيا ماركسية الانحياز السياسي أقصى اليسار المشاركة في الحكم المشاركة في الحكومة نع…
American legal philosopher (1931–2013) This article is about the legal philosopher. For the author, see Ronald W. Dworkin. Ronald DworkinDworkin in 2008BornRonald Myles Dworkin(1931-12-11)December 11, 1931Providence, Rhode Island, U.S.DiedFebruary 14, 2013(2013-02-14) (aged 81)London, EnglandEducationHarvard University (AB, JD)Magdalen College, Oxford (BA)AwardsHenry J. Friendly Medal (2005)Holberg International Memorial Prize (2007)Balzan Prize (2012)EraContemporary philosophyRegionWeste…
Inseguimento a squadreMelbourne 1956 Informazioni generaliLuogoOlympic Park Velodrome, Melbourne Periodo3 - 4 dicembre 1956 Partecipanti16 squadre da 16 nazioni Podio Leandro FagginValentino GasparellaAntonio DomenicaliFranco Gandini Italia Michel VermeulinJean-Claude LecanteRené BianchiJean Graczyk Francia Donald BurgessMike GambrillJohn GeddesTom Simpson Gran Bretagna Edizione precedente e successiva Helsinki 1952 Roma 1960 Voce principale: Ciclismo ai Giochi dell…
Gary BurtonLahir(1943-01-23)23 Januari 1943 Anderson, Indiana, Amerika SerikatPekerjaanPemusik Jazz Gary Burton (lahir 23 Januari 1943) adalah seorang pemain vibrafone jazz asal Amerika. Ia dikenal sebagai salah satu perintis musik Jazz fusion, dan penemu teknik bermain vibrafon secara pianistik. Ia memainkan vibrafon dengan empat pemukul, sebelumnya hanya digunakan teknik dengan dua pemukul, maka ia dianggap sebagai penemu dari teknik bermain tersebut. Dalam dunia pendidikan musik jazz, ia juga…
American jazz pianist and composer (1928–2014) Horace SilverPortrait by Dmitri Savitski, 1989Background informationBorn(1928-09-02)September 2, 1928Norwalk, Connecticut, U.S.DiedJune 18, 2014(2014-06-18) (aged 85)New Rochelle, New York, U.S.GenresJazz, hard bop, mainstream jazz, soul jazz, jazz fusionOccupation(s)Musician, composer, arrangerInstrument(s)PianoYears active1946–2004LabelsBlue Note, Silveto, Emerald, Columbia, Impulse!, VerveWebsitehoracesilver.comMusical artist Horace Ward…
Edgar Henry Schein (Zurigo, 5 marzo 1928 – Palo Alto, 26 gennaio 2023[1]) è stato uno psicologo statunitense. Uno dei suoi principali interessi fu la cultura organizzativa. Indice 1 Biografia 2 Opere principali 2.1 Le forme dell'aiuto. Come costruire e sostenere relazioni efficaci 2.2 La consulenza di processo. Come costruire le relazioni d'aiuto e promuovere lo sviluppo organizzativo 2.3 Culture d'impresa. Come affrontare con successo le transizioni e i cambiamenti organizzativi 2.4 …
For other uses, see Chesapeake, Virginia (disambiguation). Independent city in Virginia, United StatesChesapeake, VirginiaIndependent cityGreat Dismal Swamp Canal FlagSealWordmarkMotto: One Increasing PurposeInteractive map of ChesapeakeChesapeakeShow map of VirginiaChesapeakeShow map of the United StatesCoordinates: 36°42′51″N 76°14′18″W / 36.71417°N 76.23833°W / 36.71417; -76.23833Country United StatesState VirginiaFounded1963 (1919 as South N…
Cet article est une ébauche concernant le sport et les Jeux olympiques. Vous pouvez partager vos connaissances en l’améliorant (comment ?) selon les recommandations du projet sport. Pour les articles homonymes, voir Comité d'organisation. De gauche à droite: Chris Allison (commissaire adjoint de la police métropolitaine), Lord Coe, Theresa May et John Armitt, président de l'ODA, lors d'une visite au Parc olympique à l'est de Londres. : Chris Allison (Metropolitan Police Assistant C…