Abstract:
A process which comprises reacting a 1,2,3,4-cyclobutane- tetracarboxylic-1,2:3,4-dianhydride [1] with an alcohol [2] in the presence of an acid catalyst to obtain a compound [3], isomerizing the compound [3] with a base catalyst into a compound [4], reacting the compound [4] with an organic acid to obtain a compound [5], and reacting the compound [5] with a dehydrating agent to obtain a 1,2,3,4-cyclobutanetetracarboxylic-1,3:2,4 -dianhydride: wherein R 1 and R 2 are each independently hydrogen, halogeno, alkyl of 1 to 10 carbon atoms, halogenated alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, phenyl, or cyano; and R 3 is alkyl of 1 to 10 carbon atoms.
Abstract:
The invention relates to a method for carrying out the synthesis of cinnamic acid esters and/or cinnamic acids by condensing aldehydes with carboxylic acid anhydrides, ferric salts being used as a catalyst.
Abstract:
A process for the preparation of optically active cyclohexylglycolate esters is described. The process utilizes carboxylic acid activation to couple (R)- or (S)-cyclohexylphenylglycolic acid (CHPGA) with 4-N,N-diethylamino butynol or other propargyl alcohol derivatives. The preparation of the hydrochloride salt is also described. In addition, a resolution process employing tyrosine methyl ester enantiomers for preparing a single enantiomer of CHPGA from racemic CHPGA is disclosed.
Abstract:
Bereitgestellt werden Duft- oder Geschmacksstoffmischungen, enthaltend (i) ( E )-2- Methyl-but-2-endicarbonsäurediester, (ii) ( Z )-2-Methyl-but-2-endicarbonsäurediester und (iii) 2-Methylenbutandicarbonsäurediester mit fruchtiger, birnenähnlicher Note, Verfahren zur Herstellung dieser Duft- oder Geschmacksstoffe oder Duft- oder Geschmacksstoffmischungen, die Verwendung der Duft- oder Geschmacksstoffmischungen zur Erzeugung einer fruchtigen, birnenähnlichen Duft- oder Geschmacksnote oder zur Herstellung einer Riechstoffmischung bzw. einem Parfümöl, kosmetischen Mittel, Auftragungsmittel, Wasch- und Reinigungsmittel, Lebensmittel, Tierfuttermittel oder pharmazeutischen Produkt sowie die daraus hergestellten Produkte, die die Duft- oder Geschmacksstoffmischungen in einer sensorisch wirksamen Menge enthalten.
Abstract:
A method for preparation of phenolic (meth)acrylates. The method comprises contacting acetic anyhydride, a phenolic compound and (meth)acrylic acid to form a reaction mixture.
Abstract:
Provided are methods and materials for the functionalization of a heteroalkane or arene using an oxidizing electrophile as a stoichiometric agent or catalyst. The reaction involves the replacement of a hydrogen atom on an sp3-hybridized carbon atom of the heteroalkane or of a hydrogen atom on an sp2-hybridized carbon atom of the arene. A main group element organometallic intermediate is formed that undergoes further conversion to a functionalized heteroalkane or arene.
Abstract:
One aspect of the present invention relates to a method for the kinetic resolution of racemic and diastereomeric mixtures of chiral compounds. The critical elements of the method are: a non-racemic chiral tertiary-amine-containing catalyst; a racemic or diastereomeric mixture of a chiral substrate, e.g., a cyclic carbonate or cyclic carbamate; and a nucleophile, e.g., an alcohol, amine or thiol. A preferred embodiment of the present invention relates to a method for achieving the kinetic resolution of racemic and diastereomeric mixtures of derivatives of alpha - and beta -amino, hydroxy, and thio carboxylic acids. In certain embodiments, the methods of the present invention achieve dynamic kinetic resolution of a racemic or diastereomeric mixture of a substrate, i.e., a kinetic resolution wherein the yield of the resolved enantiomer or diastereomer, respectively, exceeds the amount present in the original mixture due to the in situ equilibration of the enantiomers or diastereomers under the reaction conditions prior to the resolution step.
Abstract:
A process for the preparation of optically active cyclohexylglycolate esters is described. The process utilizes carboxylic acid activation to couple (R)- or (S)-cyclohexylphenylglycolic acid (CHPGA) with 4-N,N-diethylamino butynol or other propargyl alcohol derivatives. The preparation of the hydrochloride salt is also described. In addition, a resolution process employing tyrosine methyl ester enantiomers for preparing a single enantiomer of CHPGA from racemic CHPGA is disclosed.