26547-47-7Relevant academic research and scientific papers
Method for preparing alkyl diether compound
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Paragraph 0048-0050, (2017/08/30)
The invention relates to the field of synthesis of alkyl diether compounds, and provides a method for preparing an alkyl diether compound with the structure shown as the formula (I). The method comprises the steps that in the presence of concentrated sulfuric acid, an ethanediol compound with the structure shown as the formula (II) and olefin C1-C8 are subjected to a haptoreaction. The alkyl diether compound prepared through the preparation method is high in purity, low in impurity content and simple in preparation process, concentrated sulfuric acid is adopted as a catalyst to replace a traditional sodium alkoxide synthesis method, and high safety and high universality are achieved. The formulas are shown in the specification, wherein R1 and R2 independently serve as alkyl groups of C1-C8, and R1 and R2 do not serve as the alkyl groups at the same time, and R'1 is hydrogen or alkyl groups of C1-C8.
Reactions of hydrogen peroxide with acetylacetone and 2- acetylcyclopentanone
Novikov,Shestak
, p. 2171 - 2190 (2014/11/07)
A reaction of acetylacetone with equimolar amount of concentrated aqueous H2O2 in both organic solvents (ButOH, AcOH) and water at various temperatures gave the corresponding 3,5-dihydroxy-1,2- dioxolanes with different configuration of stereogenic centers. In the pres-ence of an excess of H2O2, 3,5-dihydroxy-1,2-dioxolanes were converted to a mixture of 5-hydroperoxy-3-hydroxy-1,2-dioxolanes and further to a mixture of dimeric 1,2-dioxolan-3-ylperoxides. All the peroxides formed exist in solutions as equilibrium mixtures with the starting reagents. A prolonged reflux of solutions of 3,5-dihydroxy-1,2-dioxolanes in ButOH in the presence of a large excess of H2O2 led to the skeletal rearrangements of the substrates to a mixture of propionic acid and hydroxyacetone, which underwent further oxidative transfor-mations. Unlike acetylacetone, 2-acetylcyclopentanone reacted with H2O2 in aqueous phase or in solutions in ButOH under thermodynamic or kinetic control with the formation of the corresponding 5-hydroperoxy-3-hydroxy- 1,2-dioxolanes, rather than 3,5-dihydroxy-1,2-di-oxolanes. Thermodynamically controlled process in solution in AcOH gave a mixture of all four possible hydroperoxyhydroxy-1,2-dioxolanes. These cyclic peroxides in solutions in ButOH or AcOH readily converted to a mixture of AcOH, glutaric, α-methyladipic, and α-hydroxy-α-methyladipic acids. An active α-hydroxylation of the substrate was observed upon reflux of a solution of 2-acetylcyclopentanone and H2O2 in AcOH.
An efficient synthesis of tert-butyl ethers/esters of alcohols/amino acids using methyl tert-butyl ether
Mallesha,Prahlada Rao,Suhas,Channe Gowda
experimental part, p. 641 - 645 (2012/02/15)
A facile synthesis of a wide variety of tert-butyl ethers and tert-butyl ester derivatives under mild conditions is described. Alcohols etherified with tert-butyl methyl ether as tert-butyl source and solvent, in the presence of sulfuric acid. Many amino acid tert-butyl esters have been synthesized by this procedure. The reaction is simple, inexpensive, easily scaled up, and proceeds without observable racemization. A green method was developed for the deprotection of this group using Amberlite resin IR 120-H as catalyst.
Making Mercury-Ptotosensitized Dehydrodimerization into an Organic Synthetic Method: Vapor Pressure Selectivity and the Behavior of Functionalized Substrates
Brown, Stephen H.,Crabtree, Robert H.
, p. 2935 - 2946 (2007/10/02)
Mercury-photosensitized dehydrodimerization in the vapor phase can be made synthetically useful by taking advantage of a simple reflux apparatus (Figure 1), in which the products promptly condense and are protected from further conversion.This vapor pressure selectivity gives high chemical selectivity even at high conversion and on a multigram scale.Mercury absorbs 254-nm light to give the 3P1 excited state (Hg*), which homolyses a C-H bond of the substrate with a 3o>2o>1o selectivity.Quantitative prediction of product mixtures in alkane dimerization and in alkane-alkane cross-dimerizations is discussed.Radical disproportionation gives alkene, but this intermediate is recycled back into the radical pool via H atom attack, which is beneficial both for yield and selectivity.The method is very efficient at constructing C-C bonds between highly substituted carbon atoms, yet the method fails if a dimer has four sets of obligatory 1,3-syn methyl-methyl steric repulsions, as in the unknown 2,3,4,4,5,5,6,7-octamethyloctane.We have extended the range of substrates susceptible to the reaction, for example to higher alcohols, ethers, silanes, partially fluorinated alcohols, and partially fluorinated ethers.We see selectivity for dimers involving C-H bonds α to O or N and for S-H over C-H.An important advantage of our experimental conditions in the case of alcohols is that the aldehyde or ketone disproportionation product (which is not subject to H. attack) is swept out of the system by the stream of H2 also produced, so it does not remain and inhibit the rate and lower the selectivity. kdis/krec is estimated for a number of radicals studied.The very hindered 3o 1,4-dimethylcyclohex-1-yl radical is notable in having a kdis/krec as high as 7.1.
Influence of the reaction temperature on some acid-catalized processes of 6-hydroxy-4-oxa-alkanal derivatives and related products. Ring contraction in 5-alkoxy-1,4-dioxepanes
Espinosa, Antonio,Gallo, A. Miguel,Campos, Joaquin,Entrena, Antonio
, p. 379 - 383 (2007/10/02)
The qualitative effect of the reaction temperature on some acid-catalized processes carried out on 6-hydroxy-4-oxa-alkanal derivatives may be rationalized by means of two simultaneous or competitive pathways which involve intermediates such as 5-alkoxy-1,4-dioxepane derivatives or vinyl dioxolanes.We describe herein an acid catalyzed contraction of the 5-isopropoxy-1,4-dioxepane ring in dioxane and different alcohol interchange reactions with 5-alkoxy-1,4-dioxepanes that also occur with ring contraction when the reaction temperature is 60 deg C or higher.The transacetalization reactions between 6-hydroxy-4-oxa-hexal ethylene acetal and 6-hydroxy-4-oxa-heptanal 1,2-propylene acetal and tert-butanol, carried out at the reflux of the reacting mixtures are also described.The results obtained suggest 2-vinyl-1,3-dioxolanes as reactive intermediates.In order to prove this hypothesis the reaction between 2-vinyl-1,3-dioxolane and tert-butanol at reflux has been stuied.It leads to the same reaction products.
