Mosher's acid, or α-methoxy-α-trifluoromethylphenylacetic acid (MTPA) is a
carboxylic acid 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 193 ...
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 or
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
Hydrogen is the chemical element wi ...
of unknown
stereochemistry 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 fie ...
.
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.
See also
*
Pirkle's alcohol
References
{{Reflist
Stereochemistry
Carboxylic acids
Trifluoromethyl compounds
Phenyl compounds