- Kinetics and Mechanism for the Alkaline Homogeneous Hydrolysis of 1,1,1-Trimethylolethane Trinitrate
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The kinetics for the alkaline homogeneous hydrolysis of 1,1,1-trimethylolethane trinitrate (MTN) in 95percent ethanol-water with sodium hydroxide concentrations between 0.25 and 2.1 M and temperatures between 50.0 and 60.0 degC have been investigated.One mole of MTN was found to react with 3 mol of base and to hydrolize by a series of consecutive and competitive bimolecular and internal cyclization reactions involving three nitrate ester intermediates to form the cyclic alcohol ether 3-methyl-3-oxetanemethanol (AE) as the final major product with only trace amounts of the expected trialcohol 1,1,1-tris(hydroxymethyl)ethane (TA).MTN and its intermediates showed good second-order rate constants for the expression -d(MTN)/dt = k1(MTN) = k2(B-)(MTN), where k1 is the first-order rate constant with excess base, B-.Relative k2 values in 95percent ethanol-water, 95percent methanol-water, and water were found to be 1.0, 0.1, and 0.01, respectively.Hydrolysis kinetics and product formation for each nitrate ester intermediate have been determined, and an overall hydrolysis mechanism for MTN is presented.
- Hoffsommer, John C.,Glover, Donald J.,Burlinson, Nicholas E.
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Read Online
- A preparation containing glycol ether pendant method of the carbonate monomer
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The invention relates to a novel synthesis method for preparing a carbonic ester monomer containing a glycol ether lateral group. The method takes trimethylol ethane as a raw material and comprises three steps of firstly preparing a midbody oxetane, then opening ring by glycol ether of different chain lengths so as to obtain diol precursor of the carbonic ester, and closing ring so as to obtain the required carbonic ester monomer. Compared with existing methods with five steps, the method only comprises three steps, thus being simpler and more convenient to operate, the raw materials are cheap and are easy to obtain, and the method is applicable to preparing monomers on a large scale; furthermore, the proportion of the materials for reaction is calculated precisely, so that high yield in each step is guaranteed.
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Paragraph 0019; 0020; 0021
(2016/10/07)
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- A new and versatile synthesis of 3-substituted oxetan-3-yl methyl alcohols
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We have developed a novel route for the efficient synthesis of pharmaceutically significant 3-substituted oxetan-3-yl methyl alcohols starting from readily available malonates. The synthesis harnesses the diversity of malonate chemistry and allows access to a range of oxetanes, which exemplifies the versatility of this procedure.
- Boyd, Scott,Davies, Christopher D.
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supporting information
p. 4117 - 4119
(2014/07/22)
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- A new and versatile synthesis of 3-substituted oxetan-3-yl methyl alcohols
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We have developed a novel route for the efficient synthesis of pharmaceutically significant 3-substituted oxetan-3-yl methyl alcohols starting from readily available malonates. The synthesis harnesses the diversity of malonate chemistry and allows access to a range of oxetanes, which exemplifies the versatility of this procedure.
- Boyd, Scott,Davies, Christopher D.
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supporting information
p. 4117 - 4119
(2015/02/19)
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- Synthesis and polymerization of alkyl halide-functional cyclic carbonates
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To increase the diversity in functional aliphatic polycarbonates, a series of novel chloro- and bromo-functional six-membered cyclic carbonate monomers were synthesized. Despite asymmetry in the monomer functionalities, homopolymerization of the monomers afforded semicrystalline polycarbonates with a high tendency to crystallize from the melt and/or on precipitation from a THF solution. Melting points were found in the 90-105 °C or 120-155 °C range for polymers comprising methyl or ethyl moieties, respectively, in the backbone. The monomers were further copolymerized with trimethylene carbonate to form random copolymers. Even among some of these random copolymers elements of semicrystallinity were found as confirmed by melting endotherms in DSC. The results clearly show that the incorporation of alkyl halide functionalities in aliphatic polycarbonates may lead to materials with a high ability to form crystallites, even in random copolymers, likely driven by polar interactions due to the presence of the halide functionalities.
- Mindemark, Jonas,Bowden, Tim
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experimental part
p. 5716 - 5722
(2012/03/26)
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- Direct hydrogenation of amides to alcohols and amines under mild conditions
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The selective, direct hydrogenation of amides to the corresponding alcohols and amines with cleavage of the C-N bond was discovered. The expected products of C-O cleavage are not formed (except as traces in the case of anilides). The reaction proceeds under mild pressure and neutral, homogeneous conditions using a dearomatized, bipyridyl-based PNN Ru(II) pincer complex as a catalyst. The postulated mechanism involves metal-ligand cooperation by aromatization- dearomatization of the heteroaromatic pincer core and does not involve hydrolytic cleavage of the amide. The simplicity, generality, and efficiency of this environmentally benign process make it attractive for the direct transformations of amides to alcohols and amines in good to excellent yields.
- Balaraman, Ekambaram,Gnanaprakasam, Boopathy,Shimon, Linda J. W.,Milstein, David
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supporting information; experimental part
p. 16756 - 16758
(2011/02/16)
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- Nonracemizable isocyanoacetates for multicomponent reactions
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Chiral ortho esters of α-isocyano acids were synthesized from commercially available Cbz-protected α-amino acids. These compounds are stable toward racemization in the Ugi 4CC in contrast to known esters of α-isocyano acids. Applying them in Ugi 4CC with subsequent deprotection gives access to dipeptides with preserved configuration at the C-terminal amino acid.
- Zhdanko, Alexander G.,Nenajdenko, Valentine G.
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supporting information; experimental part
p. 884 - 887
(2009/07/04)
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- Process for the production of 3-alky-3-hydroxymethyloxetanes
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A process is described for the production of 3-alkyl-3-hydroxymethyloxetanes of the general formula (1), in which R1 denotes a linear or branched C1-C12 alkyl group, which process comprises reacting a trimethylolalkane of the general formula (2),(HO-CH2)3C-R1(2)in which R1 is defined as above, with a dialkyl carbonate of the general formula (3),R2-O-(C=O)-O-R2(3)in which R2 denotes a linear or branched C1-C4 alkyl group, in the presence of a basic catalyst, wherein in a first stage the reaction mixture is stirred for at least 6 hours with refluxing at a temperature of 90-120 DEG C., in a second stage the alcohol formed R2OH is distilled off at the same temperature and in a third stage the product formed is decarboxylated and deoligomerised at a temperature of 125-150 DEG C. and the desired 3-alkyl-3-hydroxymethyloxetane is simultaneously distilled off.
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- Geminal Substituent Effects, 11. The Anomeric Effect in Orthoesters - The Concept of Geminal Pairwise Interactions for the Interpretation of Standard Enthalpies of Formation
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New enthalpies of formation ΔH0f(g) are provided for the series of orthoesters 2a-2f, 3 and 4 from their enthalpies of combustion ΔH0c and their enthalpies of vaporization ΔH0vap or enthalpies of sublimation ΔH0sub.From these data and from literature data the following new thermochemical increments were calculated -1>: CH -106.4, C -103.7, and C -124.5.In addition the increment C -167.1 was calculated from literature data for ΔH0f(g) of the orthocarbonates 9a and 9b.The anomeric stabilization derived from these results and from previous results for acetals and ketals are reported in Table 3. - A new concept of additive structural increments for the quantitative analysis of the group increments of hydrocarbons, ethers, acetals, and ketals is proposed.It is shown that the increments for CH3, CH2, CH, and C groups with their different neighboring atoms (see Table 4) are determined by the number of hydrogen atoms in the group and by the number of pairwise geminal interactions between all atoms attached to the central carbon atom. - Using this procedure for orthoesters and orthocarbonates, deviations from additivity for the geminal interaction between oxygen atoms, i.e. the anomeric effect, are observed. - Keywords: Anomeric effect; Enthalpies of formation; Geminal substituents, energetic interaction of; Increments, thermochemical, of orthoesters; Group increments, interpretation of
- Rakus, Klaus,Verevkin, Sergey P.,Peng, Wei-Hong,Beckhaus, Hans-Dieter,Ruechardt, Christoph
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p. 2059 - 2068
(2007/10/03)
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- Synthesis of ω-Acetyl-α-methylenpolyene Carboxylic Esters
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The α-methylenpolyene carboxylic acids 1 and 2 are highly active against Gram-positive bacteria.If this activity arises from an interference with the cell membranes, then an abrupt change in biological properties is to be expected with growing chain length of simple model compounds.To make these tests possible, we describe here the synthesis of a series of homologue esters of type 40.Their synthesis was achieved by Wittig reactions of polyene α,ω-dialdehydes 6 with acetylmethylentriphenylphosphoran 5a and the protected carboxymethylmethylen triphenylphosphonium salt 8.
- Laatsch, Hartmut,Pudleiner, Alke
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p. 663 - 677
(2007/10/02)
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- Method of synthesizing nitrato alkyl oxetanes
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Nitrato alkyl oxetanes are synthesized directly from the corresponding hyxy alkyl oxetanes by nitrating the hydroxy alkyl oxetane under non-acidic anhydrous conditions. A hydroxy alkyl oxetane is reacted with an anhydrous nitrate ester of a carboxylic acid at temperatures below about 10° C. The product of the method, nitrato alkyl oxetane, is produced in relatively high yield without opening of the oxetane ring.
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- Cyclic Trimerization of Oxetanes
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Conditions for obtaining the optimum yield of the cyclic trimer in the cationic oligomerization of oxetanes have been determined.At moderate dilution (0.05 M) with catalytic quantities of BF3 in CH2Cl2, the yield of the cyclic trimer (1,5,9-trioxacyclododecane) from oxetane could be increased to 50percent at the expense of the cyclic tetramer (1,5,9,13-tetraoxacyclohexadecane), 12percent, and polymer.In contrast, 3,3-dimethyloxetane consumed the BF3 catalyst, which had to be renewed, producing, in a slow reaction, a homologous series of fluorohydrins, together with cyclic oligoethers.The fluorohydrins cyclized if treated with gaseous BF3 before work-up, boosting the isolated yields to 20percent cyclic trimer and 8percent cyclic tetramer.With PF5 in CH2Cl2 the catalyst was stable and the reaction fast, and no fluorohydrins were formed; no cyclic trimer but 73percent cyclic tetramer could be isolated.Other solvents (benzene, CHCl=CCl2, CH2ClCH2Cl), other catalysts (SbF5, AlEt3) and other oxetanes (3-methoxymethyl-3-methyloxetane, 3-halomethyl-3-methyloxetane) were also examined.
- Dale, Johannes,Fredriksen, Siw B.
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- The Synthesis of Oxiranes and Oxetanes from 1,2- or 1,3-Halohydrins Using Organoantimony(V) Alkoxide
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Tetraphenylstibonium methoxide (1) is an effictive reagent for the synthesis of oxiranes and oxetanes from the corresponding 1,2- and 1,3-halohydrins, respectively.As the reaction conditions are neutral, oxiranes bearing an ester moiety were obtained intact without undergoing solvolysis.In addition, oxetanes, whose preparation was not generally facile, were formed in good yields under mild conditions (60-80 deg C).
- Fujiwara, Masahiro,Hitomi, Kazuhisa,Baba, Akio,Matsuda, Haruo
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p. 106 - 109
(2007/10/02)
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- A NEW GENERAL SYNTHETIC ROUTE TO BRIDGED CARBOXYLIC ORTHO ESTERS.
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Acylation of the readily available 3-methyl-3-hydroxymethyl oxetane (2) leads to the corresponding oxetane esters (3) which rearrange smoothly in the presence of boron trifluoride etherate in methylene chloride at -15 deg C to form ortho esters of the 2,6,7-trioxabicyclooctane series (4).
- Corey, E. J.,Raju, Natarajan
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p. 5571 - 5574
(2007/10/02)
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