Potassium Tert-butoxide In Tert-butyl Alcohol Research Articles

Intramolecular Cyclization of Furfuryl 2‐Propynyl Ether.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A highly selective aerobic oxidation process catalyzed by electron-deficient nitroarenes via single electron transfer processes.

A versatile and simple method for aerobic oxidation of various aromatics containing an oxygen-functionalized benzylic carbon is reported. Results from oxidation experiments with methyl aryl ketones, benzaldehydes, benzylic alcohols, and mandelic acid are reported; all provide high yields of the corresponding aromatic carboxylic acids. By means of response surface methodology and mechanistic interpretation it is revealed that the oxidation process operates catalytically using electron-deficient nitroarenes, such as 1,3-dinitrobenzene, 1,2,3-trifluoro-4-nitrobenzene, and 2,4-difluoro-1-nitrobenzene, with molecular oxygen as the terminal oxidant. The reaction is carried out in a basic solution of potassium tert-butoxide in tert-butyl alcohol. Since the terminal oxidant is molecular oxygen and only 5-10 mol % of, e.g., 1,3-dinitrobenzene as catalyst is used, the new method represents an environmentally benign alternative to, for example, the well-known haloform reaction. The method is also a convincing alternative when transition metal free conditions are required.

Intramolecular Cyclization of Furfuryl 2-Propynyl Ether

Intramolecular cyclization of furfuryl 2-propynyl ether in the presence of a catalytic amount ofpotassium tert-butoxide in tert-butyl alcohol gives 3a'6-epoxy-1'3-dihydro-6H-isobenzofuran. The cyclizationis presumed to be favored by preliminary isomerization of the 2-propynyl group into allenyl. Heating of thecyclization product with excess potassium tert-butoxide in tert-butyl alcohol results in cleavage of the epoxybridge with formation of 6-hydroxy-1'3-dihydroisobenzofuran.

Using secondary alpha deuterium kinetic isotope effects to determine the stereochemistry of an E2 reaction; the stereochemistry of the E2 reaction of 1-chloro-2-phenylethane with potassium tert-butoxide in tert-butyl alcohol

Isotopic labelling studies have shown that the E2 reaction of 1-chloro-2-phenylethane with potassium tert-butoxide in tert-butyl alcohol occurs via an anti-periplanar stereochemistry. This demonstrates that the different secondary alpha deuterium kinetic isotope effects found for the high and low base concentrations and in the presence of 18-crown-6 ether are because of changes in transition state structure that occur when the form of the reacting base changes rather than to a change in the stereochemistry of the reaction.Key words: E2 reaction, stereochemistry, secondary alpha deuterium kinetic isotope effects, transition state.

Stereocontrol with phosphine oxides: synthesis of optically active cyclopropyl ketones

Treatment of β-keto γ′-hydroxy phosphine oxides, or silylated hemiacetal derivatives of these compounds, with potassium tert-butoxide in tert-butyl alcohol leads to the formation of cyclopropyl ketones. The synthesis of optically active 1,2-di- and 1,2,3-trisubstituted cyclopropyl ketones is described. The reaction is kinetically controlled and the ring-closure is generally stereospecific. A model is described to explain the stereochemical course of the reaction.

General and Facile Synthesis of Indoles with Oxygen-Bearing Substituents at the Benzene Moiety

Indoles with oxygen-bearing substituents such as a methoxy or (triisopropylsilyl)oxy group at all of the positions of the benzene moiety were synthesized by cyclization of tert-butyl methoxy(or (triisopropylsilyl)oxy)-2-((trimethylsilyl)ethynyl)phenyl)carbamates with potassium tert-butoxide in tert-butyl alcohol. The (ethynylphenyl)carbamates were synthesized by the palladium-catalyzed reaction of (trimethylsilyl)acetylene and the corresponding (iodophenyl)carbamates, which were selectively synthesized by directed lithiation of the phenylcarbamates and subsequent iodination.

Photochromic heterocyclic fulgides. Part 8. The condensation of 2,6-dichlorobenzaldehyde with diethyl [1-(2,5-dimethyl-3-furyl)ethylidene]succinate to give 6-chloro-2-(2,5-dimethyl-3-furyl)-1H-benzocycloheptene-3,4-dicarboxylic anhydride and photochromic (7S,7aS)-7-(2,6-dichlorophenyl)-2,4,7a-trimethyl-7,7a-dihydrobenzofuran-5,6-dicarboxylic anhydride

The dark red photochromic (7S,7aS)-7-(2,6-dichlorophenyl)-2,4,7a-trimethyl-7,7a-dihydrobenzofuran-5,6-dicarboxylic anhydride has been synthesised by the Stobbe condensation of 2,6-dichlorobenzaldehyde with diethyl [1-(2,5-dimethyl-3-furyl)ethylidene]succinate in the presence of potassium tert-butoxide in tert-butyl alcohol. When tert-butyl alcohol is replaced by toluene, 6-chloro-2-(2,5-dimethyl-3-furyl)-1H-benzocycloheptene-3,4-dicarboxylic anhydride is produced. Use of an aprotic solvent provides a new general method of preparing 2-substituted 6-chloro-1H-benzocycloheptene-3,4-dicarboxylic anhydrides via a mechanism involving nucleophilic substitution of chlorine in 2,6-dichlorobenzaldehyde, followed by intramolecular condensation.

Synthesis of cedranoid sesquiterpenes. V. The biotols

Reduction of dimethyl 3-hydroxy-4,4,8-trimethyl-6-oxo-cis-bicyclo[3.3.0]octa-2,7-diene-1,2-dicarboxylate (8) with lithium and ammonia gives dimethyl 3-hydroxy-4,4,exo-8-trimethyl-6-oxo-cis-bicyclo[3.3.0]oct-2-ene-1,2-dicarboxylate (9), which on acetylation, reduction with sodium borohydride, and methanolysis gives dimethyl 3,exo-6-dihydroxy-4,4,exo-8-trimethyl-cis-bicyclo[3.3.0]oct-2-ene-1,2-dicarboxylate (12). This on 2-decarbomethoxylation followed by treatment with lithium acetylide in the presence of cerium trichloride gives methyl 3-ethynyl-3,exo-6-dihydroxy-4,4,exo-8-trimethyl-cis-bicyclo[3.3.0]octane-1-carboxylate (21), which on hydration, diacetylation, and treatment with tri-n-butyltin hydride and azoisobutyronitrile is converted to methyl exo-6-acetoxy-3-acetyl-4,4,exo-8-trimethyl-cis-bicyclo[3.3.0]octane-1-carboxylate (31). Methanolysis of 31. tert-butyldimethylsilylation, and reaction with potassium tert-butoxide in tert-butyl alcohol gives exo-4-tert-butyldimethylsilyloxy-exo-2,6,6-trimethyl[5.3.11,5]undecane-8,10-dione (35). This on treatment with lithium aluminum hydride followed by oxidation and hydrogenation provides the corresponding 10-deoxo compound, 39. Reaction of this with methyllithium, dehydration, and desilylation with hydrogen fluoride in acetonitrile gives a mixture of (±)-α-biotol (1) and (±)-β-biotol (2); desilylation with hydrogen chloride in methanol gives solely (±)-1.

Stereochemistry and mechanisms in eliminations from some 1,2-dihalo-1,2-diphenylethanes promoted by potassium tert-butoxide in tert-butyl alcohol

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereochemistry and mechanisms in eliminations from some 1,2-dihalo-1,2-diphenylethanes promoted by potassium tert-butoxide in tert-butyl alcoholEnrico Baciocchi and Renzo RuzziconiCite this: J. Org. Chem. 1984, 49, 18, 3395–3398Publication Date (Print):September 1, 1984Publication History Published online1 May 2002Published inissue 1 September 1984https://doi.org/10.1021/jo00192a033RIGHTS & PERMISSIONSArticle Views201Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Medium basicity effects on the transition state structure of E2 reactions. Kinetic study of the reaction of 1-chloro-1-phenyl-2-arylethanes with crown ether complexed potassium tert-butoxide in tert-butyl alcohol

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMedium basicity effects on the transition state structure of E2 reactions. Kinetic study of the reaction of 1-chloro-1-phenyl-2-arylethanes with crown ether complexed potassium tert-butoxide in tert-butyl alcoholSergio Alunni, Enrico Baciocchi, and Piero PerucciCite this: J. Org. Chem. 1977, 42, 12, 2170–2172Publication Date (Print):June 1, 1977Publication History Published online1 May 2002Published inissue 1 June 1977https://doi.org/10.1021/jo00432a035RIGHTS & PERMISSIONSArticle Views53Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (441 KB) Get e-Alerts Get e-Alerts

Correction. Kinetic Study of Elimination Reactions Promoted by Crown Ether Complexed Potassium tert-Butoxide in tert-Butyl Alcohol

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCorrection. Kinetic Study of Elimination Reactions Promoted by Crown Ether Complexed Potassium tert-Butoxide in tert-Butyl AlcoholSergio Alunni, Enrico Baciocchi, and Piero PerucciCite this: J. Org. Chem. 1976, 41, 25, 4052Publication Date (Print):December 1, 1976Publication History Published online29 October 2003Published inissue 1 December 1976https://doi.org/10.1021/jo00887a621RIGHTS & PERMISSIONSArticle Views25Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (98 KB) Get e-Alerts Get e-Alerts

Kinetic study of elimination reactions promoted by crown ether complexed potassium tert-butoxide in tert-butyl alcohol

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetic study of elimination reactions promoted by crown ether complexed potassium tert-butoxide in tert-butyl alcoholSergio Alunni, Enrico Baciocchi, and Piero PerucciCite this: J. Org. Chem. 1976, 41, 15, 2636–2638Publication Date (Print):July 1, 1976Publication History Published online1 May 2002Published inissue 1 July 1976https://doi.org/10.1021/jo00877a027RIGHTS & PERMISSIONSArticle Views192Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (448 KB) Get e-Alerts Get e-Alerts

Position of the equilibrium during the migration of double bonds in the pyrazoline ring

Data characterizing the position of the equilibrium between Δ2- and Δ1-pyrazolines with alkyl substituents in different positions, which is established under the influence of potassium tertbutoxide in tert-butyl alcohol at 90°C, were obtained. 3-Alkyl-Δ2-pyrazolines are thermodynamically more stable than their isomers with different positions of the double bond, so that the fraction of the latter in equilibrium mixtures does not exceed 1–2%, and they are practically completely isomerized to the 3-Alkyl-Δ2-substituted derivatives. If the position of the side chains excludes the possibility of the formation of 3-alkyl-Δ2-pyrazolines by migration of the double bond (4-alkyl- and 5,5-dialkyl-substituted compounds), the fraction of Δ1-pyrazolines in the equilibrium rises appreciably and reaches 12% for 3,3-diethyl-Δ1-pyrazoline.

Syntheses of Polymers Containing 1, 2-Diphenoxyethane

Syntheses of polymers using 1, 2-diphenoxyethane (1) as the starting naterial are descrided. (1) was prepared in an excellent yield by the condensation of phenol with ethylene bromide in the prsence of NaOH using dimethyl sulfoxide (DMSO) -H2O medium1, 2-Diphenoxyethane-p, p'-diethylene oxide (4) was obtained by the attack of sulfonium-ylide on p, p'-diformyl-1, 2-diphenoxyethane (3), which was prepared by the condensation of p-hydroxybenzaldehyde with ethylene bromide.p, p'-Dichloromethyl-1, 2-diphenoxyethane (2), obtained by the dichloromethylation of (1) with formaldehyde and HCl, was converted to bisphenol (5), and (5) was converted further to polyester (6) and diglycidyl ether (7).(2) was treated with triphenylphosphine to give quaternary phosphonium salt (10), which was reacted with (3) as an example of Wittig reaction.Furthermore, polyether (8) or polysulfide (9) was synthesized by the condensation of (2) with phenolphthalein or Na2S p, p'-Dicyanomethy1-1, 2-diphenoxyethane (12), derived from (2), was treated with formaldehyde to give dimethylol compound (14) and a cross-linked polymer (15).Polyester (13) was also obtained by the reaction of (12) with 1, 6-hexanediol.Lastly, (12) was condensed with (2) in the presence of potassium tert-butoxide in tert-butyl alcohol to give a polymer (16) which has no solvent.

A micromethod for identification of hydroxy acids

A micromethod for the identification of hydroxy acids is described. The method depends on converting the hydroxy acid to the corresponding bromo acid with phosphorus tribromide and then dehydrobrominating the bromo acid with potassium tert-butoxide in tert-butyl alcohol. The position of the hydroxyl group and the chain length of the hydroxy acid are established by identifying the products obtained on ozonolysis and hydrogenation of the dehydrated product.

Fluorometric determination of Δ 4-3-ketosteroids

A simple fluorometric procedure for the quantitative estimation of Δ 4-3-ketosteroids is described, based on the reaction with potassium tert-butoxide in tert-butyl alcohol. The method is applicable to the determination of testosterone, progesterone, and the biologically active adrenocortical C 21 steroids, and is sensitive to 0.01 μg. of steroid.