. "4"^^ . "Meldrum's acid or 2,2-dimethyl-1,3-dioxane-4,6-dione is an organic compound. The compound was first made in 1908 by Andrew Norman Meldrum by a condensation reaction of malonic acid with acetone in acetic anhydride and sulfuric acid. Meldrum misidentified the structure as a \u03B2-lactone of \u03B2-hydroxyisopropylmalonic acid. The correct structure is shown on this page.As an alternative to its original preparation, Meldrum's acid can be synthesized from malonic acid, isopropenyl acetate, and catalytic sulfuric acid. Meldrum's acid has a high acidity with a pKa of 4.97. Meldrum's acid high acidity was long considered \"anomalous\" given it is 8 orders of magnitude more acidic than the highly related compound, dimethyl malonate (whose aqueous pKa is around 13). In 2004, Ohwada and coworkers resolved the Meldrum acid anomaly by performing several calculations. Ohwada noticed that the energy-minimizing conformation structure of the compound places the alpha proton's \u03C3CH orbital in the proper geometry to align with the \u03C0*CO, so that the ground state poses unusually strong destabilization of the C-H bond.Because of its great acidity, Meldrum's acid, like malonic acid, can serve as a reactant in Knoevenagel condensations."@en . "1/C6H8O4/c1-6(2)9-4(7)3-5(8)10-6/h3H2,1-2H3"^^ . . . . "1"^^ . . . "2.2"^^ . . . "Vorlage:Infobox Chemikalie/Summenformelsuche vorhandenMeldrums\u00E4ure ist eine organische Verbindung, die nach ihrem Entdecker Andrew Norman Meldrum benannt ist. Sie wurde erstmals 1908 durch Kondensation von Malons\u00E4ure mit Aceton in Acetanhydrid in Anwesenheit von Schwefels\u00E4ure hergestellt. Da Meldrum zun\u00E4chst von einem \u03B2-Lacton mit einer freien Carboxylgruppe ausging, wird die Verbindung f\u00E4lschlich als S\u00E4ure bezeichnet. Die Struktur wurde dann 1948 korrigiert.Meldrums\u00E4ure besitzt eine vergleichsweise hohe C-H-Acidit\u00E4t mit einem pKs-Wert von 4,97. Der analoge Malons\u00E4urediethylester weist hingegen nur einen pKs-Wert von etwa 13 auf. Erst im Jahr 2004 konnte dieses Ph\u00E4nomen durch Rechnungen erkl\u00E4rt werden.Wegen ihrer hohen C-H-Acidit\u00E4t reagiert Meldrums\u00E4ure, \u00E4hnlich wie Malons\u00E4ure, mit Carbonylverbindungen in einer Knoevenagel-Kondensation. Mit Carbons\u00E4urechloriden reagiert sie in Anwesenheit von Pyridin zur Acyl-Meldrums\u00E4ure. Wird diese in Alkoholen erhitzt, entsteht ein \u03B2-Ketoester. Meldrums\u00E4ure ist damit eine Ausgangsverbindung zur Synthese dieser Stoffklasse. Die \u03B2-Ketoester kommen in der Knorr-Pyrrolsynthese zum Einsatz."@de . . "A Meldrum-sav barn\u00E1sfeh\u00E9r szil\u00E1rd anyag (op. 96\u00B0C). V\u00EDzben j\u00F3l old\u00F3dik. Er\u0151s sav, amit sok\u00E1ig \u201Erendellenesnek\u201D tartottak, mert sokkal er\u0151sebb, mint a hozz\u00E1 legjobban hasonl\u00EDt\u00F3 dimetil-malonsav. A rejt\u00E9lyt 2004-ben Ohwada oldotta meg munkat\u00E1rsaival, k\u00FCl\u00F6nb\u00F6z\u0151 sz\u00E1m\u00EDt\u00E1sok alapj\u00E1n."@hu . "Knorr pyrrole synthesis"@fr . "en"@fr . "33"^^ . . . "6"^^ . . . . . . "L'acido di Meldrum (o 2,2-dimetil-1,3-diossano-4,6-dione) \u00E8 un diestere ciclico, avente formula bruta C6H8O4."@it . . . . . "Meldrum's acid or 2,2-dimethyl-1,3-dioxane-4,6-dione is an organic compound. The compound was first made in 1908 by Andrew Norman Meldrum by a condensation reaction of malonic acid with acetone in acetic anhydride and sulfuric acid. Meldrum misidentified the structure as a \u03B2-lactone of \u03B2-hydroxyisopropylmalonic acid."@en . "Meldrums\u00E4ure"@de . . . "4.97"^^ . . . . . . . . . "2,2-dim\u00E9thyl-1,3-dioxane-4,6-dione"@fr . . "synth\u00E8se de pyrrole de Knorr"@fr . "Acide de Meldrum"@fr . . "Acido di Meldrum"@it . . . . . "4467514"^^ . . "acide de Meldrum"@fr . "acide de Meldrum"@fr . . "\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\uFF08\u30E1\u30EB\u30C9\u30E9\u30E0\u3055\u3093\u3001Meldrum's acid\uFF09\u3001\u3082\u3057\u304F\u306F 2,2-\u30B8\u30E1\u30C1\u30EB-1,3-\u30B8\u30AA\u30AD\u30B5\u30F3-4,6-\u30B8\u30AA\u30F3 \u306F\u5206\u5B50\u5F0F C6H8O4 \u3067\u8868\u3055\u308C\u308B\u6709\u6A5F\u5316\u5408\u7269\u3067\u3042\u308B\u3002\u3053\u306E\u5316\u5408\u7269\u306F1908\u5E74\u306B\u30B9\u30B3\u30C3\u30C8\u30E9\u30F3\u30C9\u306E\u5316\u5B66\u8005\u30A2\u30F3\u30C9\u30EA\u30E5\u30FC\u30FB\u30CE\u30FC\u30DE\u30F3\u30FB\u30E1\u30EB\u30C9\u30E9\u30E0 (Andrew Norman Meldrum) \u306B\u3088\u308A\u3001\u7121\u6C34\u9162\u9178\u3068\u786B\u9178\u4E2D\u3067\u30DE\u30ED\u30F3\u9178\u3068\u30A2\u30BB\u30C8\u30F3\u306E\u4ED8\u52A0\u8131\u96E2\u53CD\u5FDC\u3092\u884C\u3063\u3066\u3044\u308B\u3068\u304D\u306B\u767A\u898B\u3055\u308C\u305F\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u306F\u03B2-\u30E9\u30AF\u30C8\u30F3\uFF08\u03B2-\u30D2\u30C9\u30ED\u30AD\u30B7\u30A4\u30BD\u30D7\u30ED\u30D4\u30EB\u30DE\u30ED\u30F3\u9178\uFF09\u3068\u69CB\u9020\u3092\u8AA4\u8A8D\u3057\u3066\u3044\u305F\u3002\u6B63\u3057\u3044\u69CB\u9020\u306F\u3053\u306E\u30DA\u30FC\u30B8\u306B\u8868\u793A\u3055\u308C\u3066\u3044\u308B\u3082\u306E\u3067\u3042\u308B\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u304C\u4F7F\u3063\u305F\u65B9\u6CD5\u306B\u5909\u308F\u308B\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306E\u88FD\u6CD5\u3068\u3057\u3066\u3001\u786B\u9178\u3092\u89E6\u5A92\u3068\u3057\u3066\u30DE\u30ED\u30F3\u9178\u3068\u9162\u9178\u30A4\u30BD\u30D7\u30ED\u30DA\u30CB\u30EB\u3092\u53CD\u5FDC\u3055\u305B\u308B\u3082\u306E\u304C\u3042\u308B\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306F\u9AD8\u3044\u9178\u89E3\u96E2\u5B9A\u6570\u3092\u6301\u3063\u3066\u3044\u308B (pKa=4.97)\u3002 \u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306F\u95A2\u9023\u3059\u308B\u307B\u304B\u306E\u30AB\u30EB\u30DC\u30CB\u30EB\u5316\u5408\u7269\u306B\u6BD4\u3079\u975E\u5E38\u306B\u9AD8\u3044\u9178\u5EA6\u3092\u793A\u3057\u3001\u9577\u3044\u9593\u3053\u308C\u306F\u7570\u5E38\u3067\u3042\u308B\u3068\u8003\u3048\u3089\u308C\u3066\u304D\u305F\u304C\u30012004\u5E74\u306B\u5927\u548C\u7530\u667A\u5F66\u3089\u306B\u3088\u3063\u3066\u89E3\u6C7A\u3055\u308C\u3066\u3044\u308B\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306F\u30DE\u30ED\u30F3\u9178\u3068\u540C\u69D8\u306B\u3001\u30AF\u30CD\u30FC\u30D5\u30A7\u30CA\u30FC\u30B2\u30EB\u7E2E\u5408\u306E\u8A66\u85AC\u3068\u3057\u3066\u7528\u3044\u3089\u308C\u308B\u3002"@ja . "Meldrum's acid"@en . "9693"^^ . . . "92599016"^^ . . "Vorlage:Infobox Chemikalie/Summenformelsuche vorhandenMeldrums\u00E4ure ist eine organische Verbindung, die nach ihrem Entdecker Andrew Norman Meldrum benannt ist. Sie wurde erstmals 1908 durch Kondensation von Malons\u00E4ure mit Aceton in Acetanhydrid in Anwesenheit von Schwefels\u00E4ure hergestellt. Da Meldrum zun\u00E4chst von einem \u03B2-Lacton mit einer freien Carboxylgruppe ausging, wird die Verbindung f\u00E4lschlich als S\u00E4ure bezeichnet."@de . "2,2-dim\u00E9thyl-1,3-dioxane-4,6-dione"@fr . . "O=C(C1)OC(C)(C)OC1=O"^^ . . . . . . . . "A Meldrum-sav barn\u00E1sfeh\u00E9r szil\u00E1rd anyag (op. 96\u00B0C). V\u00EDzben j\u00F3l old\u00F3dik. Er\u0151s sav, amit sok\u00E1ig \u201Erendellenesnek\u201D tartottak, mert sokkal er\u0151sebb, mint a hozz\u00E1 legjobban hasonl\u00EDt\u00F3 dimetil-malonsav. A rejt\u00E9lyt 2004-ben Ohwada oldotta meg munkat\u00E1rsaival, k\u00FCl\u00F6nb\u00F6z\u0151 sz\u00E1m\u00EDt\u00E1sok alapj\u00E1n."@hu . . . "O=COCOC1=O"@fr . "\u30E1\u30EB\u30C9\u30E9\u30E0\u9178"@ja . "\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\uFF08\u30E1\u30EB\u30C9\u30E9\u30E0\u3055\u3093\u3001Meldrum's acid\uFF09\u3001\u3082\u3057\u304F\u306F 2,2-\u30B8\u30E1\u30C1\u30EB-1,3-\u30B8\u30AA\u30AD\u30B5\u30F3-4,6-\u30B8\u30AA\u30F3 \u306F\u5206\u5B50\u5F0F C6H8O4 \u3067\u8868\u3055\u308C\u308B\u6709\u6A5F\u5316\u5408\u7269\u3067\u3042\u308B\u3002\u3053\u306E\u5316\u5408\u7269\u306F1908\u5E74\u306B\u30B9\u30B3\u30C3\u30C8\u30E9\u30F3\u30C9\u306E\u5316\u5B66\u8005\u30A2\u30F3\u30C9\u30EA\u30E5\u30FC\u30FB\u30CE\u30FC\u30DE\u30F3\u30FB\u30E1\u30EB\u30C9\u30E9\u30E0 (Andrew Norman Meldrum) \u306B\u3088\u308A\u3001\u7121\u6C34\u9162\u9178\u3068\u786B\u9178\u4E2D\u3067\u30DE\u30ED\u30F3\u9178\u3068\u30A2\u30BB\u30C8\u30F3\u306E\u4ED8\u52A0\u8131\u96E2\u53CD\u5FDC\u3092\u884C\u3063\u3066\u3044\u308B\u3068\u304D\u306B\u767A\u898B\u3055\u308C\u305F\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u306F\u03B2-\u30E9\u30AF\u30C8\u30F3\uFF08\u03B2-\u30D2\u30C9\u30ED\u30AD\u30B7\u30A4\u30BD\u30D7\u30ED\u30D4\u30EB\u30DE\u30ED\u30F3\u9178\uFF09\u3068\u69CB\u9020\u3092\u8AA4\u8A8D\u3057\u3066\u3044\u305F\u3002\u6B63\u3057\u3044\u69CB\u9020\u306F\u3053\u306E\u30DA\u30FC\u30B8\u306B\u8868\u793A\u3055\u308C\u3066\u3044\u308B\u3082\u306E\u3067\u3042\u308B\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u304C\u4F7F\u3063\u305F\u65B9\u6CD5\u306B\u5909\u308F\u308B\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306E\u88FD\u6CD5\u3068\u3057\u3066\u3001\u786B\u9178\u3092\u89E6\u5A92\u3068\u3057\u3066\u30DE\u30ED\u30F3\u9178\u3068\u9162\u9178\u30A4\u30BD\u30D7\u30ED\u30DA\u30CB\u30EB\u3092\u53CD\u5FDC\u3055\u305B\u308B\u3082\u306E\u304C\u3042\u308B\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306F\u9AD8\u3044\u9178\u89E3\u96E2\u5B9A\u6570\u3092\u6301\u3063\u3066\u3044\u308B (pKa=4.97)\u3002 \u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306F\u95A2\u9023\u3059\u308B\u307B\u304B\u306E\u30AB\u30EB\u30DC\u30CB\u30EB\u5316\u5408\u7269\u306B\u6BD4\u3079\u975E\u5E38\u306B\u9AD8\u3044\u9178\u5EA6\u3092\u793A\u3057\u3001\u9577\u3044\u9593\u3053\u308C\u306F\u7570\u5E38\u3067\u3042\u308B\u3068\u8003\u3048\u3089\u308C\u3066\u304D\u305F\u304C\u30012004\u5E74\u306B\u5927\u548C\u7530\u667A\u5F66\u3089\u306B\u3088\u3063\u3066\u89E3\u6C7A\u3055\u308C\u3066\u3044\u308B\u3002\u30E1\u30EB\u30C9\u30E9\u30E0\u9178\u306F\u30DE\u30ED\u30F3\u9178\u3068\u540C\u69D8\u306B\u3001\u30AF\u30CD\u30FC\u30D5\u30A7\u30CA\u30FC\u30B2\u30EB\u7E2E\u5408\u306E\u8A66\u85AC\u3068\u3057\u3066\u7528\u3044\u3089\u308C\u308B\u3002"@ja . . . "200"^^ . . . "L'acido di Meldrum (o 2,2-dimetil-1,3-diossano-4,6-dione) \u00E8 un diestere ciclico, avente formula bruta C6H8O4."@it . . . . "Meldrum-sav"@hu . "2.2"^^ . . . "8"^^ .