Emde degradation
Encyclopedia
The Emde degradation is a method for the reduction
of a quaternary ammonium cation
to a tertiary amine
with sodium amalgam
This organic reaction
was first described in 1909 by the German chemist Hermann Emde and was for a long time of great importance in structure elucidation of many alkaloid
s, for example that of ephedrine
.
Alternative reducing agent
s exist for this reaction; for instance, lithium aluminium hydride
.
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
of a quaternary ammonium cation
Quaternary ammonium cation
Quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure NR4+, R being an alkyl group or an aryl group. Unlike the ammonium ion and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged,...
to a tertiary amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
with sodium amalgam
Sodium amalgam
Sodium amalgam, commonly denoted Na, is an alloy of mercury and sodium. The term amalgam is used for alloys, intermetallic compounds, and solutions involving mercury as a major component. Sodium amalgam is often used in reactions as strong reducing agents with better handling properties compared...
Organic reaction
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions. In organic synthesis,...
was first described in 1909 by the German chemist Hermann Emde and was for a long time of great importance in structure elucidation of many alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
s, for example that of ephedrine
Ephedrine
Ephedrine is a sympathomimetic amine commonly used as a stimulant, appetite suppressant, concentration aid, decongestant, and to treat hypotension associated with anaesthesia....
.
Alternative reducing agent
Reducing agent
A reducing agent is the element or compound in a reduction-oxidation reaction that donates an electron to another species; however, since the reducer loses an electron we say it is "oxidized"...
s exist for this reaction; for instance, lithium aluminium hydride
Lithium aluminium hydride
Lithium aluminium hydride, commonly abbreviated to LAH or known as LithAl, is an inorganic compound with the chemical formula LiAlH4. It was discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters,...
.