Demjanov Rearrangement

Demjanov Rearrangement Mechanism

Demjanov Rearrangement Mechanism: One of the most familiar methods for the generation of carbonium ions is the determination of primary amines by means of nitrous acid. In many cases the initially formed carbonium ion undergo rearrangement to yield the rearranged products. Thus n-propylamine on treatment with nitrous acid yields some n-propyl alcohol together with a major proportion of isopropyl alcohol. This reaction forms the basis of Demjanov's method of expanding and contracting alicyclic ring systems (Demjanov Rearrangement). 
Demjanov Rearrangement Mechanism

when cyclobutylmethyl amine is treated with nitrous acid it gives both cyclobutylcarbinol (2) and cylcopentanol (4) besides methylenecyclobutene  (1) and cyclopentene (3).
Demjanov Rearrangement Mechanism
Demjanov Rearrangement Mechanism

The Reimer-Tiemann reaction: Reaction and its Mechanism

Reimer-Tiemann Reaction Phenols on reaction with chloroform in the presence of sodium hydroxide (or potassium hydroxide) solution give hydro...