- Method for preparing dimethyl 3-methylpentyl-2-enedionate
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The invention provides a method for preparing dimethyl 3-methylpentyl-2-enedionate. The method has the advantages of easy availability of raw materials, high yield and less waste residues, and is suitable for industrial production.
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Paragraph 0027; 0030-0032
(2018/07/30)
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- POLYMERS PREPARED FROM MEVALONOLACTONE AND DERIVATIVES
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Described herein polymer precursor compounds (aka polymer building blocks) of derived from biobased compounds, and specifically biobased mevalonolactone and its related derivatives. Through oxidation these biobased precursors can be reacted to yield building blocks for (unsaturated-) polyesters, polyester polyols and polyamides, as well as precursors for glycidyl esters and omega-alkenyl esters. Through reduction, these biobased precursors can be reacted to yield building blocks for (unsaturated-) polyesters, polyester polyols, polycarbonates, as well as precursors for glycidyl ethers and omega-alkenyl ethers. Through nucleophilic ring opening and/or amidation, these biobased precursors can be reacted to yield building blocks for polyester polyols, chain-extender for polyurethanes, or polyester-amides.
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Page/Page column 52; 53
(2016/06/06)
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- Allosteric effects in binuclear homo- and heterometallic triple-stranded lanthanide podates
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This work illustrates a simple approach for deciphering and exploiting the various free energy contributions to the global complexation process leading to the binuclear triple-stranded podates [Ln2(L9)]6+ (Ln is a trivalent lanthanide). Despite the larger microscopic affinities exhibited by the binding sites for small Ln3+, the stability constants measured for [Ln2(L9)]6+ decrease along the lanthanide series; a phenomenon which can be ascribed to the severe enthalpic penalty accompanying the intramolecular cyclization around small Ln(III), combined with increasing anticooperative allosteric interligand interactions. Altogether, the microscopic thermodynamic characteristics predict β1,1,1 La,Lu,L9/β1,1,1Lu,La,L9 = 145 for the ratio of the formation constants of the target heterobimetallic [LaLu(L9)] 6+ and [LuLa(L9)]6+ microspecies, a value in line with the quantitative preparation (>90%) of [LaLu(L9)]6+ at millimolar concentrations. Preliminary NMR titrations indeed confirm the rare thermodynamic programming of a pure heterometallic f-f′ complex.
- Ryan, Patrick E.,Canard, Gabriel,Koeller, Sylvain,Bocquet, Bernard,Piguet, Claude
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p. 10012 - 10024
(2012/10/30)
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- An improved synthesis of a mixture of diethyl (Z)- and (E)-3-methylglutaconates from ethyl acetoacetate
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A simple, efficient two-step synthesis of a mixture of diethyl (Z)- and (E)-3-methylglutaconates from isodehydroacetic acid in 83% yield is described. On the basis of this synthesis an improved procedure for the preparation of a mixture of (Z)- and (E)-3-methylglutaconic acids from ethyl acetoacetate in 44% overall yield was elaborated.
- Kuchkova,Morari,Vlad
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p. 1221 - 1222
(2007/10/02)
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- A Stereospecific Synthesis of (+/-)-Abscisic Acid
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A convenient separation of (E)- and (Z)-3-methylpent-2-enedioic acids was devised, and it was shown that with acetyl chloride or thionyl chloride the (Z)-acid yields the cyclic anhydride while the (E)-acid forms 6-chloro-4-methylpyran-2-one.The chloropyranone by conventional chemistry gave 4-methyl-6-(2'-oxopropyl)pyran-2-one which condensed with 4-methylpent-3-en-2-one in the presence of pyrrolidine, yielding 4-methyl-6-(2',6',6'-trimethyl-4'-oxocyclohex-2'-enyl)pyran-2-one.Oxidation with selenium dioxide or t-butyl chromate then gave 6-(1'-hydroxy-2',6',6'-trimethyl-4'-oxocyclohex-2'-enyl)-4-methylpyran-2-one, which on reduction by lithium aluminium hydride and reoxidation afforded (+/-)-abscisic acid stereospecifically.
- Cornforth, John,Hawes, John E.,Mallaby, Richard
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p. 179 - 185
(2007/10/02)
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