cas 763-32-6, 3-METHYL-3-BUTEN-1-OL | Articles data

Articles about 763-32-6Total 62 be found

Article title
Article abstract
Author
Journal number and time
Download

A comparative study of an MCM-41 anchored quaternary ammonium chloride/SnCl4 catalyst and its silica gel analogue
A novel reusable Lewis acid catalyst has been prepared by the heterogenization of a Lewis acid/tetrapropylammonium adduct; anchoring of tin chloride on quaternary ammonium chloride functionalized MCM-41 yielded a catalyst with higher activity compared to the corresponding silica analogue in terms of turnover rates and product yield in the Prins condensation of isobutene and formaldehyde to isoprenol.
Jyothi,Kaliya,Herskowitz,Landau
p. 992 - 993
(2001)
Read Online

A Lewis acid catalyst anchored on silica grafted with quaternary alkylammonium chloride moieties
Resistance to leaching and re-usability are characteristic of the novel heterogeneous Lewis acid catalyst that was prepared by anchoring tin(IV) chloride on silica grafted with tetraalkylammonium or pyridinium chloride groups. The catalyst displays high activity and selectivity in the synthesis of 3-methyl-3-buten-1-ol by the Prins condensation of isobutene with formaldehyde [Eq. (1)].
Jyothi, Thundi M.,Kaliya, Mark L.,Landau, Miron V.
p. 2881 - 2884
(2001)
Read Online

Revisiting the Structural Evolution of Hydrotalcite-Derived Mixed Metal Oxides upon Alkali Metal Doping and Its Impact on Base Catalysis
The structural evolution of classic coprecipitation-derived Mg?Al mixed oxide (MMO) upon doping of different alkali metals in a wide level (1–20 wt.%) was revisited. The pristine lateral MMO of aggregates into particulates, accompanied with the dramatic loss of the surface areas and the formation of aluminates. These phenomena become severer with the decrease of the atomic radius. The formation of NaAlO2 likely occurs via the gradual dealumination of the MMO, which is highly dependent on both the dopant content and the activation temperature. This leads to ultimately a new ensemble with MgO as the core decorated by NaAlO2 in the outer surfaces at high Na doping level and above 973 K. When evaluated in the base-catalyzed transesterification and acylation model reactions, the Na-doped MMO show enhanced performance and a plateau at increasing doping that might be explained by an interplay between the number and strength of strong basicity.
Ding, Yunjie,Lin, Ronghe,Lv, Yali,Mou, Xiaoling,Yu, Qing
(2021/12/24)

METHOD FOR PRODUCING GAMMA, DELTA-UNSATURATED ALCOHOL
A method for producing a γ,δ-unsaturated alcohol of formula (2): wherein R1 to R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and optionally substituted with a hydroxy group, an alkenyl group having 2 to 10 carbon atoms and optionally substituted with a hydroxy group, or an aryl group having 6 to 12 carbon atoms and optionally substituted with a hydroxy group, provided that R1 and R3 may bond to each other to form a ring, through a reaction of an α-olefin of formula (1) and formaldehyde under a heating condition: the method including a step of bringing the α-olefin into contact with an aqueous formaldehyde solution in the presence of an alcohol having 3 to 10 carbon atoms, with the aqueous formaldehyde solution being subjected to preheating at 30 to 220° C. before the step.
-
Paragraph 0107; 0111

(2020/03/09)

PROCESS TO RECOVER HIGH QUALITY 3-METHYL-BUT-3-EN-1-OL
The presently claimed invention relates to a process for the recovery of 3-methyl-3-buten- l-ol from a stream obtained in the production of 3-methyl-3-buten-l-ol from 2-methylprop- 1-ene and formaldehyde, by treating the stream with an amine catalyst.
-
Page/Page column 13

(2020/04/25)

PROCESS TO RECOVER 3-METHYL-BUT-3-EN-1-OL
The presently claimed invention relates to a process for the recovery of 3-methyl-3-buten- -ol from a stream comprising (Z)-3-methylpent-2-ene-1,5-diol, (E)-3-methylpent-2-ene-,5-dioland 3-methylenepentane-1,5-diolby treating the stream with isobutene and water.
-
Page/Page column 10-11

(2020/10/09)

A method for utilizing the isobutylene and methanol for preparing 3 - methyl -3 - butene -1 - ol (by machine translation)
The invention discloses a method of using isobutylene and methanol for preparing 3 - methyl - 3 - butene - 1 - ol, its steps mainly are: first nitrogen purging stainless steel high-pressure reaction vessel, replacing the air in the reaction vessel; the methanol liquid added in a reaction vessel, then the isobutylene gas into the reaction container, the high-pressure nitrogen pressurization, make isobutene liquefied, with methanol to form a mixed solution; adding a catalyst in a fixed bed, and then pumped to the isobutene with methanol mixed solution in a fixed bed, into the oxygen-containing gas to react, cooling discharging after completion of the reaction, distillation is 3 - methyl - 3 - butene - 1 - ol. The method of the invention using methanol instead of toxic formaldehyde, environment friendly, the preparation cost is reduced, simplifying the process, and using the fixed bed reactor, can be continuously produced, has high production efficiency and product quality. (by machine translation)
-
Paragraph 0040-0062

(2019/04/17)

PROCESS FOR RECOVERING 3-METHYLBUT-3-EN-1-OL
The present invention relates to a process for recovering 3-methylbut-3-en-1 -ol from a feed stream F1 comprising 3-methylbut-3-en-1 -ol, one or more solvents, water, and isobutene, wherein 3-methylbut-3-en-1 -ol, the one or more solvents and water are separated from isobutene by distillation, the process comprising subjecting the feed stream F1 to distillation conditions in a distillation unit, obtaining a bottoms stream B1 which is enriched in -methylbut-3-en-1 -ol, in the one or more solvents and in water compared to the feed stream F1 subjec The present invention relates to a process for recovering 3-methylbut-3-en-1 -ol from a feed stream F1 comprising 3-methylbut-3-en-1 -ol, one or more solvents, water, and isobutene, wherein 3-methylbut-3-en-1 -ol, the one or more solvents and water are separated from isobutene by distillation, the process comprising subjecting the feed stream F1 to distillation conditions in a distillation unit, obtaining a bottoms stream B1 which is enriched in -methylbut-3-en-1 - ol, in the one or more solvents and in water compared to the feed stream F1 subjected to distillation conditions, and a top stream T1 which is enriched in isobutene, further subjecting the bottoms stream B1 to distillation conditions in a second distillation unit and obtaining a bottoms stream B2 which is enriched in 3-methylbut-3-en-1-ol compared to the bottoms stream B1 and a top stream T2 which is enriched in water compared to the bottoms stream B1, further subjecting the bottoms stream B2 to distillation conditions in a third distillation unit and obtaining a top stream T3 which is enriched in 3-methylbut-3-en-1-ol compared to the bottoms stream B2 and a bottoms stream B3. ted to distillation conditions, and a top stream T1 which is enriched in isobutene, further subjecting the bot- toms stream B1 to distillation conditions in a second distillation unit and obtaining a bottoms stream B2 which is enriched in 3-methylbut-3-en-1-ol compared to the bottoms stream B1 and a top stream T2 which is enriched in water compared to the bottoms stream B1, further subjecting the bottoms stream B2 to distillation conditions in a third distillation unit and obtaining a top stream T3 which is enriched in 3-methylbut-3-en-1-ol compared to the bottoms stream B2 and a bottoms stream B3.
-
Page/Page column 57

(2019/02/25)

METHOD FOR PRODUCING CONJUGATED DIENE
A method for producing a conjugated diene, including a step A of allowing an α-olefin and formaldehyde to react with each other to produce a γ,δ-unsaturated alcohol in the presence of an alcohol; and a step B of subjecting the γ,δ-unsaturated alcohol to a dehydration reaction at 135 to 210° C. in the presence of an aqueous solution of an acidic catalyst.
-
Paragraph 0065-0068

(2018/10/30)

PROCESS FOR PREPARING AN UNSATURATED ALCOHOL
The present invention relates to a process for preparing an unsaturated alcohol, preferably 3,7- dimethyl-2,6-octadienal, by contacting an alkene, preferably isobutene, with formaldehyde in the presence a condensation catalyst comprising a zeolitic material comprising the framework structure of which comprises a tetravalent element Y other than Si.
-
Page/Page column 35-36

(2018/09/21)

PRODUCTION OF 2-SUBSTITUTED 4-HYDROXY-4-METHYL-TETRAHYDROPYRANS FROM STARTING MATERIALS CONTAINING 2-ALKYL-4,4-DIMETHYL-1,3-DIOXANES
The present invention relates to a method for preparing 2-substituted 4-hydroxy-4-methyltetrahydropyrans from starting materials comprising at least one 2-alkyl-4,4-dimethyl-1,3-dioxane.
-
Paragraph 0266

(2017/06/15)

PRODUCTION OF 2-SUBSTITUTED 4-METHYL-TETRAHYDROPYRANS FROM STARTING MATERIALS CONTAINING 2-ALKYL-4,4-DIMETHYL-1,3-DIOXANES
The invention relates to a method for producing 2-substituted 4-methyltetrahydropyrans of general formula (I) from starting materials containing at least one 2-substituted 4,4-dimethyl-1,3-dioxane of general formula (II).
-
Paragraph 0257

(2017/04/13)

PRODUCTION METHOD FOR GAMMA, DELTA-UNSATURATED ALCOHOLS
Provided is a method from which a γ,δ-unsaturated alcohol having a much more smaller amount of inclusion of formic acid and a formic acid ester and having a high purity can be obtained in a high yield. Specifically, provided is a method for producing a γ,δ-unsaturated alcohol by causing a reaction between an α-olefin and formaldehyde, the method including a step of bringing a reaction liquid obtained through the reaction into contact with an alkaline aqueous solution so as to provide an aqueous solution having pH of 9 to 13.
-
Paragraph 0084

(2018/01/11)

Method for synthesizing 3-methyl-3-butene-1-ol
The invention discloses a method for synthesizing 3-methyl-3-butene-1-ol. In an existing method, methanol used as a solvent is easily condensed with formaldehyde produced by polyoxymethylene depolumerization at the higher temperature to produce methylal, and thus, the yield of products is affected. According to the method, in a solvent containing methylal, a formaldehyde-containing methylal solution is obtained after polyoxymethylene depolumerization, and then, the methylal solution and isobutene are subjected to a Prins condensation reaction to produce 3-methyl-3-butene-1-ol. The methylal solvent is adopted, formaldehyde produced by polyoxymethylene depolumerization is dissolved under the proper condition, continuous feeding is facilitated, the problem that the reaction yield is decreased due to the fact that methanol is condensed with formaldehyde at the high temperature to produce methylal is solved, and risks of condenser blockage and the like when tertiary butanol is used as a solvent during recovery are avoided.
-
Paragraph 0021; 0022; 0023; 0024; 0025

(2017/09/05)

PROCESSES FOR CONVERSION OF BIOLOGICALLY DERIVED MEVALONIC ACID
The invention relates to a process comprising reacting mevalonic acid, or a solution comprising mevalonic acid, to yield a first product or first product mixture, optionally in the presence of a solid catalyst and/or at elevated temperature and/or pressure. The invention further relates to a process comprising: (a) providing a microbial organism that expresses a biosynthetic mevalonic acid pathway; (b) growing the microbial organism in fermentation medium comprising suitable carbon substrates, whereby biobased mevalonic acid is produced; and (c) reacting said biobased mevalonic acid to yield a first product or first product mixture.
-
Paragraph 0138

(2016/06/13)

A 3-methyl-3-butene-1-ol for the preparation of
The invention discloses a preparation method for 3-methyl-3-butene-1-ol. The preparation method comprises the following steps of causing water, transition metal salt, isobutylene and formaldehyde to enter a condensation reactor, and performing condensation reaction under the conditions of 300 to 360 DEG C and 5 to 25MPa, wherein the transition metal salt is one or two or more of vanadium, chromium, iridium, iron, rhenium, ruthenium, cadmium, platinum, cerium, praseodymium, neodymium, samarium, europium, terbium, dysprosium, thulium and the like, the condensation reaction can be completely implemented within 1 to 100s under the synergistic catalysis of transition metal ions and [H3O], and only a small amount of isobutylene is required; performing light component removal, dehydration and heavy component removal on condensation reaction liquid to obtain high-purity 3-methyl-3-butene-1-ol.
-
Paragraph 0059; 0060

(2017/02/09)

3-methyl-3-buten-1-ol production method
The invention relates to a 3-methyl-3-buten-1-ol production method and belongs to the technical field of water reducer synthesis. The method comprises that isoprene and hydrogen chloride as raw materials undergo an addition reaction to produce a mixture of 1-chloroisopentene and 3-chloroisopentene, the reaction product undergoes a hydrolysis reaction so that the chloroisopentene is transformed into methyl butenol and prenyl alcohol, and the hydrolysis products undergo an isomerization reaction to produce a finished product. The method is used for 3-methyl-3-buten-1-ol synthesis and has the advantages of simple processes, abundant raw material sources, low production cost and high reaction yield.
-
Paragraph 0029; 0038; 0031; 0042; 0044; 0034; 0035

(2016/12/16)

Continuous 3-methyl-3-buten-1-ol production method
The invention discloses a continuous 3-methyl-3-buten-1-ol production method.The method includes that paraformaldehyde is put in corresponding alcoholic solution with sodium methylate or sodium ethoxide mass concentration being 1-5% to form methanal hemiacetal solution by depolymerization and condensation; isobutene and methanal hemiacetal are put in a tubular reactor to generate the target product 3-methyl-3-buten-1-ol by one-step reaction under the action of catalysts; the product generated in the reaction stage is cooled and then fed into an isobutene recovery tower, a light component removal tower and a product refining tower sequentially.By the continuous 3-methyl-3-buten-1-ol production method, the defects of low heat and mass transfer efficiency, high reaction pressure, more side reactions, low production efficiency and the like in an intermittent tank process are overcome, and continuous 3-methyl-3-buten-1-ol production with the isobutene and the methanal hemiacetal serving as raw materials is realized.
-
Paragraph 0031; 0032

(2017/01/12)

A 3-methyl-3-butene-1-ol synthesis method
The invention discloses a method for synthesizing 3-methyl-3-butene-1-ol. The method comprises the following steps of preparing a paraformaldehyde isopropanol solution, adding a catalyst, carrying out the reaction of the paraformaldehyde isopropanol solution with isobutene, and purifying a crude 3-methyl-3-butene-1-ol. The added catalyst can be aluminium isopropoxide, aluminium propoxide, aluminium ethylate, aluminium methoxide, basic aluminium chloride and aluminium hydroxide, and the addition amount of the catalyst is 0.1-1% of the mass of formaldehyde. The reaction condition of the method is not critical, and the catalysts containing acids, alkalis and halogens are not used. According to the method, the requirement on production equipment is not high, and the low-temperature low-pressure reaction condition has low requirement on the safety of industrial production, and the investment on equipment is low. The method has the advantages that the selectivity and the conversion rate are high, the reaction selectivity of formaldehyde is more than or equal to 95.6%, the conversion rate of formaldehyde is more than or equal to 96.7%, the purity of purified 3-methyl-3-buten-1-ol is more than 99.5%, and the content of water in 3-methyl-3-buten-1-ol is less than 0.1%.
-
Paragraph 0050-0055

(2017/06/20)

Hydrogenation of allyl alcohols catalyzed by aqueous palladium and platinum nanoparticles
A series of Pd and Pt nanoparticles (NPs) was prepared starting from the corresponding metal ions and lignosulphonates; NPs were tested as catalysts for allyl alcohols hydrogenation in water at room temperature and pressure. All NPs were active with sharp differences in conversions and selectivities: Pt NPs formed mainly saturated alcohols, whereas Pd NPS were more active, but less selective, forming, in addition to saturated alcohols, also isomeric unsaturated alcohols and aldehydes, both saturated and unsaturated.
Di Pietrantonio, Krystel,Coccia, Francesca,Tonucci, Lucia,D'Alessandro, Nicola,Bressan, Mario
p. 68493 - 68499
(2015/09/01)

PREPARATION METHOD OF 3-METHYL-3-BUTEN-1-OL
The present invention relates to a manufacturing method of 3-methyl-3-buten-1-ol, comprising a step of making t-butanol and a solid-phase paraformaldehyde react with each other between 20 and 200 degree Celsius under catalysts including metal halide selected from a group consisting of tin, zinc, magnesium, aluminium, silicon, gallium, indium and scandium wherein the manufacturing method is allowed to manufacture 3-methyl-3-buten-1-ol in a high yield and an efficient process without additional processes like removing moisture or solvent only by using a single process.COPYRIGHT KIPO 2015
-
Paragraph 0031; 0032; 0033; 0038

(2016/10/24)

Process For The Production Of Isoprenol From Mevalonate Employing a Diphosphomevalonate Decarboxylae
Described is a method for the enzymatic production of isoprenol using mevalonate as a substrate and enzymatically converting it by a decarboxylation step into isoprenol as well as the use of an enzyme which is capable of catalyzing the decarboxylation of mevalonate for the production of isoprenol from mevalonate. Furthermore described is the use of mevalonate as a starting material for the production of isoprenol in an enzymatically catalysed reaction. Also disclosed is a method for the production of isoprene comprising the method for the production of isoprenol using mevalonate as a substrate and enzymatically converting it by a decarboxylation step into isoprenol and further comprising the step of converting the produced isoprenol into isoprene as well as a method for the production of isoamyl alcohol comprising the method for the production of isoprenol using mevalonate as a substrate and enzymatically converting it by a decarboxylation step into isoprenol and further comprising the step of converting the produced isoprenol into isoamyl alcohol.
-
Paragraph 0083-0086; 0097; 0103-0108

(2016/03/04)

Process for preparing 3-substituted 2-alkenals, in particular prenal
The present invention to a process for preparing 2-alkenals of the formula I in which R1 is selected from hydrogen and C1-C4-alkyl; and R2 is selected from hydrogen, C1-C12-alkyl, C2-C12-alkenyl, C4-C8-cycloalkyl and C6-C10-aryl, wherein C1-C12-alkyl and C1-C12-alkenyl may be substituted with C5-C7-cycloalkyl or C5-C7-cylcoalkenyl ; comprising dehydrogenating an alkenol of the formula II, an alkenol of the formula III or a mixture thereof, wherein R1 and R2 are each as defined above, wherein the alkenol II, the alkenol II or a mixture thereof is brought into contact with a catalytic system comprising at least one ligand and a metal compound selected from ruthenium(II) compounds and iridium(I) compounds, and wherein the hydrogen formed during the dehydrogenation is removed from the reaction mixture by: i) reaction with a reoxidant selected from C3-C12-alkanones, C4-C9-cycoalkanones, benzaldehyde and mixtures thereof; and/or ii) purely physical means.
-
Paragraph 0124

(2013/06/06)

PROCESS FOR PREPARING 3-SUBSTITUTED 2-ALKENALS, IN PARTICULAR PRENAL
The present invention to a process for preparing 2-alkenals of the formula (I) in which R1 is selected from hydrogen and C1-C4-alkyl; and R2 is selected from hydrogen, C1-C12-alkyl, C2-C12-alkenyl, C4-C8-cycloalkyl and C6-C-10 aryl, wherein C1-C12-alkyl and C1-C12-alkenyl may be substituted with C5-C7-cycloalkyl or C5-C7-cylcoalkenyl; comprising dehydrogenating an alkenol of the formula (II), an alkenol of the formula (III) or a mixture thereof, wherein R1 and R2 are each as defined above, wherein the alkenol II, the alkenol III or a mixture thereof is brought into contact with a catalytic system comprising at least one ligand and a metal compound selected from ruthenium(II) compounds and iridium(I) compounds, and wherein the hydrogen formed during the dehydrogenation is removed from the reaction mixture by: i) reaction with a reoxidant selected from C3-C12-alkanones, C4-C9-cycoalkanones, benzaldehyde and mixtures thereof; and/or ii) purely physical means.
-
Page/Page column 26

(2013/06/06)

MONOMER COMPOSITION CONTAINING UNSATURATED POLYALKYLENE GLYCOL ETHER-BASED MONOMER, METHOD FOR PRODUCING COMPOSITION THEREOF, POLYMER OBTAINED USING COMPOSITION THEREOF, AND METHOD FOR PRODUCING POLYMER THEREOF
To provide a monomer composition containing an unsaturated polyalkylene glycol ether-based monomer and having excellent stability. Provided is a monomer composition containing an unsaturated polyalkylene glycol ether-based monomer represented by the following chemical formula (1): [in-line-formulae]YO(R1O)nR2??(1)[/in-line-formulae] [in the formula, Y represents an alkenyl group having 2 to 7 carbon atoms; R1O represents one or two or more types of oxyalkylene groups having 2 to 18 carbon atoms; n represents an average addition mole number of oxyalkylene groups and is a number of 5 to 500; and R2 represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms], an organic acid, and water, and having a pH of 4 to 13.
-
Page/Page column

(2013/07/25)

Palladium-catalyzed cross-coupling of unactivated alkenes with acrylates: Application to the synthesis of the C13-C21 fragment of palmerolide A
Diene to meet: A palladium-catalyzed cross-coupling reaction between alkyl-substituted olefins and acrylates gives the corresponding butadienes in moderate yield and stereoselectivity. This atom-economical reaction, which forms C sp 2-C sp 2 bonds, tolerates a wide range of allylic and homoallylic alcohols, and acrylates (see scheme; TIPS =triisopropylsilyl). The methodology was applied to the synthesis of the C13-C21 fragment of palmerolide A.
Wen, Zhen-Kang,Xu, Yun-He,Loh, Teck-Peng
supporting information
p. 13284 - 13287,4
(2012/12/12)

Palladium-catalyzed cross-coupling of unactivated alkenes with acrylates: Application to the synthesis of the C13-C21 fragment of palmerolide A
Diene to meet: A palladium-catalyzed cross-coupling reaction between alkyl-substituted olefins and acrylates gives the corresponding butadienes in moderate yield and stereoselectivity. This atom-economical reaction, which forms C sp 2-C sp 2 bonds, tolerates a wide range of allylic and homoallylic alcohols, and acrylates (see scheme; TIPS =triisopropylsilyl). The methodology was applied to the synthesis of the C13-C21 fragment of palmerolide A.
Wen, Zhen-Kang,Xu, Yun-He,Loh, Teck-Peng
supporting information
p. 13284 - 13287
(2013/01/15)

PREPARATION OF HOMOALLYL ALCOHOLS IN THE PRESENCE OF NONCOVALENTLY SUPPORTED IONIC LIQUID PHASE CATALYSTS UNDER GAS-PHASE REACTION CONDITIONS
Process for preparing homoallyl alcohols by catalyzed reaction of alkenes with aldehydes or ketones, wherein the reaction is carried out in the gas phase in the presence of noncovalently supported ionic liquid phase catalysts.
-
Page/Page column 6

(2012/04/11)

Redox isomerization of allylic alcohols catalyzed by osmium and ruthenium complexes containing a cyclopentadienyl ligand with a pendant amine or phosphoramidite group: X-ray structure of an η3-1-hydroxyallyl- metal-hydride intermediate
Complexes [MCl2(η6-p-cymene)]2 (M = Os (1a), Ru (1b)) react with Li(C5H4CH2CH 2NHMe) (LiCpN) and KPF6 to give the sandwich derivatives [M(η5-CpN)(η6-p-cymene)] PF6 (M = Os (2a), Ru (2b)). Treatment of 2a and 2b with (2,2--biphenol)PCl leads to [M(η5-CpP) (η6-p-cymene)]PF6 (M = Os (3a), Ru (3b); Cp P = C5H4CH2CH2N(Me)P(2,2- -biphenol)). The photolysis of 2a, 2b, 3a, and 3b in acetonitrile produces the release of the p-cymene group and the coordination of the cyclopentadienyl pendant substituent to the metal center to afford [M(η5-C 5,κ-N-CpN)(CH3CN)2]PF 6 (M = Os (4a), Ru (4b)) and [M(η5-C 5,κ-P-CpP)(CH3CN)2]PF 6 (M = Os (5a), Ru (5b)). Complex 4a, which has been characterized by X-ray diffraction analysis, is a more efficient catalyst precursor than 4b for the redox isomerization of primary allylic alcohols, while the latter is more efficient than the former for the redox isomerization of secondary allylic alcohols. From the catalytic solutions containing 4a and 2-methyl-2-propen-1-ol, the η3-1-hydroxyallyl complex [OsH(η5-C 5,κ-N-CpN){η3-CH2C(CH 3)CHOH}]PF6 (6) has been crystallized and characterized by spectroscopic methods and X-ray diffraction analysis. The structure shows a N-HO hydrogen bond (2.22 a) between the NH-hydrogen atom of the coordinated pendant amine group and the oxygen atom of the hydroxy substituent of the allyl ligand.
Batuecas, Maria,Esteruelas, Miguel A.,Garcia-Yebra, Cristina,Onate, Enrique
scheme or table
p. 2166 - 2175
(2010/07/03)

Rapid, highly efficient and stereoselective deoxygenation of epoxides by ZrCl4/NaI
An effective and highly chemoselective method is described for the rapid deoxygenation of different epoxides to the corresponding olefins using ZrCl 4/NaI in anhydrous CH3CN, in excellent yields and with retention of relative stereochemistry.
Firouzabadi, Habib,Iranpoor, Nasser,Jafarpour, Maasoumeh
p. 4107 - 4110
(2007/10/03)

Stereochemical analysis of isopentenyl diphosphate isomerase type II from Staphylococcus aureus using chemically synthesized (S)- and (R)-[2- 2H]Isopentenyl diphosphates
(Chemical Equation Presented) To study the catalysis of isopentenyl diphosphate (IPP) isomerase type II from Staphylococcus aureus, which is a flavoprotein catalyzing the interconversion of IPP and dimethylallyl diphosphate, we have chemically synthesized (S)- and (R)-[2-2H]IPP and carried out stereochemical analysis of the reaction. Our results show that the C-2 deprotonation of IPP by this enzyme is pro-R stereospecific, suggesting a similar stereochemical course as the type I enzyme.
Kao, Chai-Lin,Kittleman, William,Zhang, Hua,Seto, Haruo,Liu, Hung-Wen
p. 5677 - 5680
(2007/10/03)

Efficient tetrahydropyranylation of alcohols and detetrahydropyranylation reactions in the presence of catalytic amount of trichloroisocyanuric acid (TCCA) as a safe, cheap industrial chemical
Preparation and cleavage of THP ethers of different hydroxy functional groups are easily and efficiently performed in the presence of trichloroisocyanuric acid (TCCA) in the absence of solvent with high yields.
Firouzabadi, Habib,Iranpoor, Nasser,Hazarkhani, Hassan
p. 3623 - 3630
(2007/10/03)

Liquid-phase isomerization of saturated and unsaturated epoxides
The liquid-phase isomerization of a variety of epoxides was studied using a complex catalyst system based on magnesium bromide and dimethylformamide. The data obtained elucidate the mechanism of the liquid-phase isomerization and show the range of oxygen-containing compounds which can be prepared through this reaction.
Mel'nik,Khvatova,Moskvichev,Srednev,Egorova
p. 167 - 169
(2007/10/03)

Isomerization of allylic alcohols to carbonyl compounds by aqueous-biphase rhodium catalysis
Isomerization of allylic and homoallylic alcohols is catalyzed by the zwitterionic Rh(I) complex (sulphos)Rh(cod) in water-n-octane to give the corresponding aldehyde or ketone in high yields and chemoselectivity. A π-allyl metal hydride mechanism is proposed on the basis of various independent experiments in both homogeneous and biphasic systems [sulphos = -O3S(C6H4)CH2C(CH2 PPh2)3].
Bianchini,Meli,Oberhauser
p. 11 - 12
(2007/10/03)

Syntheses with organoboranes. VII, monohydroboration of conjugated dienes with catecholborane catalyzed by complexes of Nickel(II) chloride and Cobalt(II) chloride with diphosphines
The monohydroboration of representative conjugated dienes 1-7 with catecholborane in the presence of SmI3, t-BuOSmI2, LaI3, Ti(OPr(i))4, iron(II), nickel(II) and cobalt(II) chloride complexes with dppe, dppp and dppb was examined. NiCl2(dppe), NiCl2(dppp) and CoCl2(dppp) shoned catalytic activity. The 1,2-addition products were obtained, no 1,4-addition was observed. The reactivity in the presence of NiCl2(dppe) decreased in the order acyclic dienes > cyclic dienes >>1-decene.
Zaidlewicz, Marek,Meller, Jerzy
p. 7279 - 7282
(2007/10/03)

Rearrangement of 1,2-Epoxy-3-methylbutane over Lithium Phosphate and Its Mechanism
Gas-phase isomerization of 1,2-epoxy-3-methylbutane over lithium phosphate at 230-360°C yields 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, and 2-methyl-3-buten-2-ol. 3-Methylbutanal, 3-methyl-2-butanone, 3-methyl-1-butanol, 3-methyl-2-butanol, isoamyl alcohols, unsaturated carbonyl compounds, isoprene, and isopentenes were also identified among the products. The isomerization mechanism is discussed in terms of acid-base difunctional catalysis. Depending on the basicity of the epoxide, the rearrangement into unsaturated alcohols proceeds either by concerted mechanism or through formation of ion pairs.
Srednev,Moskvichev,Yas'kina,Egorova
p. 947 - 954
(2007/10/03)

Isomerization of 1,2-epoxy-3-methylbutane on lithium phosphate
It has been shown that, during the isomerization of 1,2-epoxy-3-methylbutane on lithium phosphate in the temperature range 290-336°C. along with the formation of 3-methyl-2-buten-1-ol and carbonyl compounds, rearrangement of the epoxide into 3-methyl-3-buten-1-ol occurs, connected with transfer of the hydride ion. The composition of the main isomerization products of the epoxide has been established. The mechanism of the reaction with the participation of acid-base centres of lithium phosphate is discussed.
Srednev,Yas'kina,Zhukov,Surovtsev,Moskvichev
p. 540 - 546
(2007/10/03)

Kinetic scheme of homogeneous acid-catalyzed transformation of isopentenols
The reactions occurring in an equilibrium mixture of 3-methyl-1-buten-3-ol and 3-methyl-2-buten-1-ol in 24-49 percent aqueous solutions of H2SO4 yield isoprene, 3-methyl-3-buten-1-ol, isobutylene, formaldehyde, 3-methylbutane-1,3-diol.Isobutylene is rapidly hydrated to give 2-methylpropan-2-ol.The presence of formaldehyde in the reaction mixture indicates that the transformations involve the reverse Prins reaction.On the basis of experimental and literature data, two most probable reactions were suggested.
Ryabova, R. S.,Osipova, G. F.,Travin, S. O.
p. 840 - 843
(2007/10/02)

The experimental detection of a retro-Prince reaction exemplified by a homogeneous acid-catalyzed decomposition of isopentenols
The occurence of the retro-Prince reaction in the transformations of an equilibrium mixture of 2-methyl-3-buten-2-ol and 3-methyl-2-buten-1-ol in 24.9percent-49percent aqueous sulfuric acid at 25 deg C has been experimentally proved. - Key words: acid catalysis; equilibrium mixture; isopentenols; Prince reaction.
Ryabova, R. S.,Osipova, G. F.
p. 311 - 313
(2007/10/02)

Cyclization of farnesyl diphosphate to pentalenene. Orthogonal stereochemistry in an enzyme-catalyzed S(E') reaction
Pentalenene synthase catalyzes the cyclization of farnesyl diphosphate to (1) the sesquiterpene hydrocarbon pentalenene (4). Separate incubations of (4S,8S)-[4,8-3H2, 4,8-14C2]farnesyl diphosphate and (4R,8R)-[4,8-3H2, 4,814C2]farnesyl diphosphate with pentalenene synthase isolated from Streptomyces UC5319 and analysis of the derived labeled pentalenenes, 4a and 4b, respectively, by chemical degradation established that H-8si of FPP was lost upon cyclization to pentalenene. Consideration of the plausible conformations of the enzymatic cyclization intermediates indicates that the electrophilic allylic addition elimination (S(E')) reaction in which the C-4,5 bond of pentalenene is formed involves an orthogonal relationship between the C-C bond being formed and the C-H bond that is ultimately broken.
Cane,Weiner
p. 118 - 127
(2007/10/02)

Application of palladium-catalyzed [3 + 2] cycloaddition technology to the elaboration of kempane diterpenes. Stereocontrolled Synthesis of (±)-3α-hydroxy-7β-kemp-8(9)-en-6-one and (±)-3β-hydroxykemp-7(8)-en-6-one
The total synthesis of three hydroxykempenones (8-10) has been accomplished. The retrosynthetic elements of the strategy focused on setting four key stereocenters in rings A and B, followed by annulation of ring C and ultimate cyclization to construct the seven-membered ring, D. Since the target molecule carries eight contiguous stereogenic centers, proper attention to stereocontrolled processes was mandatory. The key features of the scheme include the palladium-catalyzed [3 + 2] cycloaddition of trimethylenemethane to an activated octalone with complete control of π-facial selectivity, fully regiospecific monooxidation of a diol with ammonium molybdate uniquely at the secondary site to provide a key hydroxy ketone, hydroxyl-directed hydride reduction of the latter intermediate in order to override a contrary kinetic preference for nucleophilic attack, avoidance of Grob fragmentation in diaxial, monofunctionalized 1,3-diols, and selective deoxygenation of a 1,3-diol. The stereochemical results featured in the cycloaddition step were elucidated preliminarily in experiments designed to probe cyclopentannulation in general. The striking kinetic stability of the α,β- and β,γ-unsaturated tetracyclic end products has been analyzed by means of molecular modeling.
Paquette, Leo A.,Sauer, Daryl R.,Cleary, Darryl G.,Kinsella, Mary A.,Blackwell, Christopher M.,Anderson, Lawrence G.
p. 7375 - 7387
(2007/10/02)

Regiochemical Control in the Reductive Cleavage of 2-Alkylated Oxetanes by Use of Trialkylaluminums. Tertiary Organolithiums with γ-Oxy Functionality
Whereas 2,2-dialkylated oxetanes are cleaved by lithium 4,4'-di-tert-butylbiphenylide to provide the primary organolithium-tertiary oxyanions, the same reaction in the presence of trialkylaluminums gives exclusively the 3-lithio-3,3-disubstituted propoxides, which are trapped by carbonyl compounds in moderate yields.
Mudryk, Boguslaw,Cohen, Theodore
p. 5760 - 5761
(2007/10/02)

On the influence of phosphoric ester groups in geranyldiphosphate biosynthesis
Elimination reactions have been performed on sulfonium salts mimicking the intermediates in the title reaction.It has been found that the direction of the elimination is strongly influenced by the phosphate residue favouring the formation of the "natural" isomer.This has been attributed to the very strong electron attracting power of the phosphoric ester group.Keywords: prenyl transferase / phosphoric esters / orientation of elimination reactions
Jacob, L.,Julia, M.,Pfeiffer, B.,Rolando, C.
p. 719 - 733
(2007/10/02)

One-Pot Conversions of (Silylmethyl)cyclopropanes to Homoallylic Alcohols and 1,4-Diols Based on Haloborane-Induced Ring Opening
The reactions of (silylmethyl)cyclopropanes with haloboranes, such as BBr3 and BHBr2, result in desilylative ring opening to give homoallylboranes and boracyclopentanes, respectively.Coupled with subsequent oxidation procedure, these reactions provide ready access to homoallylic alcohols and 1,4-diols.
Ryu, Ilhyong,Hirai, Akira,Suzuki, Haruhisa,Sonoda, Noboru,Murai, Shinji
p. 1409 - 1410
(2007/10/02)

PHOTOENOLISATION OF CONJUGATED ESTERS: SYNTHESIS OF A SAN JOSE SCALE PHEROMONE BY PARTIALLY REGIO-CONTROLLED PHOTOCHEMICAL DECONJUGATION.
The photochemical deconjugation reaction of an α,β-unsaturated ester is applied to the synthesis of one of the components of the San Jose scale pheromone, compound 1.The use of a weak organic base as a means of control of the regiochemistry of the deconjugation reaction was demonstrated.
Lombardo, Domenic A.,Weedon, Alan C.
p. 5555 - 5558
(2007/10/02)

One-Pot Synthesis of Substituted Homoallylic Alcohols (3-Alkenols) and 1,1-Dideuterio-3-alkenols
The reaction of the lithium enolate of ethyl acetate with various α-chlorocarbonyl compounds followed by in situ reduction with lithium aluminium hydride or deuteride and then lithiation with lithium powder leads, after hydrolysis, to homoallylic alcohols in a regioselective manner.
Barluenga, Jose,Alvarez, Flora,Concellon, Jose M.,Yus, Miguel
p. 654 - 655
(2007/10/02)

CONDENSATION OF ISOBUTENE WITH FORMALDEHYDE IN NITROMETHANE.
It is shown that condensation of isobutene with formaldehyde in nitromethane proceeds at a high rate and selectivity. The qualitative and quantitative compositions of the products formed in water and in nitromethane indicate that the reaction mechanisms in the two media are different.
Zakoshanskii,Idlis
p. 1769 - 1771
(2007/10/02)

Effect of 3- and 4-Methyl Substituents on the Photocyclization of N-(3-Alkenyl)phthalimides: Synthesis of Pyrroloisoindoles and Pyridoisoindoles
Photolysis of N-(3-alkenyl)phthalimides 2 in methanol gave tetrahydro-5H-pyrroloisoindol-5-ones 3 and/or tetrahydropyridoisoindol-6(2H)-ones 4 depending on the degree of substitution at the olefin carbons of 2.Electron transfer followed by the anti-Markownikoff addition of methanol is proposed as a possible pathway.Keywords - N-(3-alkenyl)phthalimide; photocyclization; pyrroloisoindole; pyridoisoindole; electron transfer; anti-Markownikoff addition
Machida, Minoru,Oda, Kazuaki,Kanaoka, Yuichi
p. 75 - 84
(2007/10/02)

SYNTHESIS OF 4-METHYL- AND 4-PHENYLTETRAHYDROPYRAN-4-OLS FROM 4,4-DIMETHYL AND 4-METHYL-4-PHENYL-1,3-DIOXANES
-
Romanov, N. A.,Kantor, E. A.,Karakhanov, R. A.,Rakhmankulov, D. L.
p. 316 - 319
(2007/10/02)

BASIC ELIMINATION OF SULFONIUM SALTS. NEIGHBOURING GROUP INFLUENCE ON REGIOSELECTIVITY.
A simple preparation of sulfonium salts functionalized by oxygenated groups is reported.The nature and the position of the latter control the regiochemistry of elimination of the sulfonium moiety leading to selective formation of Saytsev or Hofmann olefins.
Badet, B.,Julia, M.,Mallet, J. M.,Schmitz, C.
p. 4331 - 4334
(2007/10/02)