Some following conversions also explain the concept of Hoffmann’s quaternary ammonium salt 
(xiv) Cope elimination
When tertiary alkylamine oxides in which one of alkyl group have
atom undergo thermal cleavage to form alkenes and hydroxyl amine.
This elimination does not require the presence of baseion, actually internal base already present inside the system as N-oxide oxygen so intramolecular base promotes a Ei elimination by path of a five membered cyclic transition state.
Above reaction follows syn stereochemistry for elimination exactly opposite to the anti elimination in Hoffmann’s regiochemistry. For example
Second isomeric cyclohexene is not formed because it is impossible for a ring hydrogen to becomes syn to the amine oxide group unless the cyclohexane ring is severely distorted. Cope elimination also form less substituted alkene same as Hoffmann’s orientation.
UREA
Basic Character
First organic compound to be synthasized in lab from inorganic compounds thus discarding
“Vital force theory” of Berzelius which said that no organic compound can be synthesized in lab. It was synthesized by Wholar’s.
On the other hand acetic acid was the first organic compound to be synthesize from elements in their free states.
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Urea is a monoamide of carbamic acid (NH2COOH) and diamide of carbonic acid H2CO3 |
Preparation
