Mosher's acid, or α-methoxy-α-trifluoromethylphenylacetic acid (MTPA) is a

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxyl ...

which was first used by

Harry Stone Mosher Harry Stone Mosher (August 31, 1915 – March 2, 2001) was an American chemist and the discoverer of Mosher's acid. Early life Mosher attended Willamette University in Salem, Oregon, where he received a bachelor's degree in chemistry in 19 ...

as a

chiral derivatizing agent A chiral derivatizing agent (CDA) also known as a chiral resolving reagent, is a chiral auxiliary used to convert a mixture of enantiomers into diastereomers in order to analyze the quantities of each enantiomer present within the mix. Analysis can ...

. It is a

chiral Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from i ...

molecule, consisting of ''R'' and ''S'' enantiomers.

Applications

As a chiral derivatizing agent, it reacts with an

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent su ...

of unknown

stereochemistry Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereo ...

to form an ester or amide. The

absolute configuration Absolute configuration refers to the spatial arrangement of atoms within a chiral molecular entity (or group) and its resultant stereochemical description. Absolute configuration is typically relevant in organic molecules, where carbon is bonde ...

of the ester or amide is then determined by proton and/or ¹⁹F

NMR spectroscopy Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. The sample is placed in a magnetic fiel ...

. Mosher's acid chloride, the

acid chloride In organic chemistry, an acyl chloride (or acid chloride) is an organic compound with the functional group . Their formula is usually written , where R is a side chain. They are reactive derivatives of carboxylic acids (). A specific example o ...

form, is sometimes used because it has better reactivity.

References

{{Reflist Stereochemistry Carboxylic acids Trifluoromethyl compounds Phenyl compounds

Applications

See also

References