3054-95-3Relevant academic research and scientific papers
Access to protected functional aldehydes by free radical additions to acrolein diethylacetal
Degueil-Castaing,Mohr,Maillard
, p. 1703 - 1712 (1992)
Free radical additions of hydrogen donor solvents (cyclohexane, dichloromethan, tetahydrofuran, dimethyl malonate and pentan-2-one) to acrolein diethylacetal allowed their 3,3 diethoxypropylation.
Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route towardcontra-Thermodynamic Olefins
Zhao, Huaibo,McMillan, Alastair J.,Constantin, Timothée,Mykura, Rory C.,Juliá, Fabio,Leonori, Daniele
supporting information, p. 14806 - 14813 (2021/09/18)
We report here a mechanistically distinct tactic to carry E2-type eliminations on alkyl halides. This strategy exploits the interplay of α-aminoalkyl radical-mediated halogen-atom transfer (XAT) with desaturative cobalt catalysis. The methodology is high-yielding, tolerates many functionalities, and was used to access industrially relevant materials. In contrast to thermal E2 eliminations where unsymmetrical substrates give regioisomeric mixtures, this approach enables, by fine-tuning of the electronic and steric properties of the cobalt catalyst, to obtain high olefin positional selectivity. This unprecedented mechanistic feature has allowed access tocontra-thermodynamic olefins, elusive by E2 eliminations.
Method for synthesizing aminopterin sodium drug intermediate acrolein diethyl acetal
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Paragraph 0007; 0015; 0016, (2017/03/14)
A method for synthesizing an aminopterin sodium drug intermediate acrolein diethyl acetal includes the following steps that 1.36 mol of sodium sulfite solution, 1.7 mol of diethyl acetal-beta-amino propionaldehyde solution (2), 2.1-2.3 mol of 2-nitrophenol solution (3), 0.5-6 mol of stannous chloride and 300 ml of acetonitrile are added into a reaction container provided with a stirrer, a thermometer and a dropping funnel, stirring speed is controlled to be 150-180 rpm, the solution temperature is raised to 130-135 DEG C, reaction is conducted for 7-9 h, standing and layering are carried out, an oil layer is extracted, saline solution washing, isopropanol washing, triethylamine washing and vacuum distillation are conducted, fractions at the temperature of 90-95 DEG C are collected, recrystallization is conducted in methylbenzene, and crystal of acrolein diethyl acetal is obtained.
Propynal equivalents and diazopropyne: Synthesis of all mono-13C isotopomers
Seburg, Randal A.,Hodges, Jonathan A.,McMahon, Robert J.
experimental part, p. 1626 - 1643 (2009/10/17)
Mechanistic and spectroscopic investigations of reactive C 3H2 hydrocarbons necessitated the preparation of diazopropyne isotopomers bearing mono-13C substitution at each of the three unique positions. The diazo compounds and their tosylhydrazone precursors were prepared from the mono-13C isotopomers of propynal (in the form of either the aldehyde or the diethyl acetal). The introduction of 13C-labeling at either alkyne position in propynal utilized the Corey - Fuchs procedure for chain homologation.
Silane coupling agent and method for preparing the same
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, (2008/06/13)
Disclosed herein are a silane coupling agent and a method of preparing the same useful for a composite organic-inorganic material. The silane coupling agent is represented by the formula of R1R2R3Si—X, wherein R1, R2, and R3, respectively, represent straight or branched alkyl having 4 to 22 carbon atoms, alkoxy, phenyl, phenyl alkoxy, benzyloxy or phenyl alkyl group. The method comprises the steps of: dissolving a vinyl derivative in a solvent under a nitrogen or argon atmosphere; and reacting the resulting solution with an alkoxysilane derivative at a temperature of 20 to 200° C. for 1 to 72 hours in the presence of a metal catalyst. Alternatively, the method comprises the steps of: dissolving alkylmagnesium halide in a solvent under a nitrogen or argon; and reacting the resulting solution with haloalkoxysilane at a temperature of ?78° C. to 50° C. for 0.1 to 5 hours.
Method of preparing optically active alpha -amino acids and alpha -amino acid derivatives
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, (2008/06/13)
PCT No. PCT/EP96/03984 Sec. 371 Date Apr. 30, 1998 Sec. 102(e) Date Apr. 30, 1998 PCT Filed Sep. 11, 1996 PCT Pub. No. WO97/10203 PCT Pub. Date Mar. 20, 1997The invention relates to a new process for the preparation of optically active amino acids and amino acid derivatives of the general formula (I), wherein *, X and R1 to R4 have the meaning given in the description. Starting from commercially obtainable (-)-menthol or (+)-menthol, the enantiomerically pure compounds of the formula (I) are obtained in high yields. The method is particularly suitable for the preparation of sterically demanding amino acids and amino acid derivatives.
Method for the preparation of 1,4-butandial
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, (2008/06/13)
The preparation of 1,4-butandial (succindialdehyde) is obtained using acrolein. The acrolein is first converted with an alkanol into 3,3-dialkoxy-1-propene and this is then hydroformylated in the presence of hydridotristriphenylphosphine-rhodiumcarbonyl mixed with triphenylphosphine or triphenylphosphite as the catalyst. The thereby obtained 4,4-dialkoxy-butanal is removed from the hydroformylation product by means of distillation and is then hydrolyzed to 1,4-butandial.
STEREOSELECTIVE FORMATION OF (E)-1-ALKENYL ETHERS. THE COUPLING REACTION OF 1,3- OR 3,3-DIETHOXY-1-PROPENE WITH GRIGNARD REAGENTS CATALYZED BY NICKEL-PHOSPHINE COMPLEX
Sugimura, Hideyuki,Takei, Hisashi
, p. 351 - 354 (2007/10/02)
1,3- or 3,3-Diethpxy-1-propene reacted with Grignard reagents in the presence of nickel-phosphine complex to give (E)-1-alkenyl ethers stereoselectively.
1-Bromo-2-ethoxycyclolithium: A Synthetic Equivalent of 2-Lithio or 3-Lithiopropenal. Application to the Synthesis of Juvenile Hormone (JH-II), β-Sinensal, and Jasmonoids.
Morizawa, Yoshitomi,Kanakura, Akihiro,Yamamoto, Hajime,Hiyama, Tamejiro,Nozaki, Hitosi
, p. 1935 - 1942 (2007/10/02)
The ethyl vinyl ether-dibromocarbene adduct was lithiated with butyllithium at -95 deg C in tetrahydrofuran.The resulting lithium carbenoid 3 was allowed to react with various electrophiles to give 1-substituted trans-1-bromo-2-ethoxycyclopropanes (1) in good yields.The trans relationship of Br and OEt groups was found particularly pertinent to the ethanolysis of 1 producing 2-substituted propenal diethyl acetal derivatives.The reaction has been applied to 1-methoxycyclohexene-dibromocarbene adducts, giving rise hereby 2-substituted 2-cyclohepten-1-one dimethyl acetals under ring enlargement.T he transformation has been utilized in the synthesis of a homoterpenoid (JH-II) or a terpenoid (β-sinensal) structure by SN2' substitution of allylic acetates with lithium dimethylcuprate(I) or iron pentacarbonyl respectively.The reaction products of 3 with aldehydes are oxidized with dimethyl sulfoxide to give cyclopropyl ketones whose ethanolysis in the presence of boron trifluoride ether complex gives β-bromo γ-keto aldehyde acetals.Debromination followed by acidic hydrolysis produces γ-keto aldehydes serving as precursors of dihydrojasmone and cis-jasmone.
