Wharton reaction
Encyclopedia
The Wharton reaction is the chemical reaction
of α,β-epoxy
-ketone
s with hydrazine
to give allylic alcohol
s. It can be used to synthesize carenol compounds.
Dupuy has developed an improved procedure.
of the Wharton reaction begins with reaction of the ketone (1) with hydrazine to form a hydrazone
(2). Rearrangement of the hydrazone gives intermediate 3, which can decompose giving off nitrogen
gas forming the desired product 4. Stork et al. have investigated the mechanism of the final decomposition and found that it can proceed by an ionic mechanism or a radical mechanism depending on reaction temperature, solvent used, and structure of intermediate 3.
Notice that the alcohol retains the configuration of the starting epoxide. The reaction is named after Peter Stanley Wharton.
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
of α,β-epoxy
Epoxide
An epoxide is a cyclic ether with three ring atoms. This ring approximately defines an equilateral triangle, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers. Simple epoxides are named from the parent compound ethylene oxide or oxirane, such as in...
-ketone
Ketone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
s with hydrazine
Hydrazine
Hydrazine is an inorganic compound with the formula N2H4. It is a colourless flammable liquid with an ammonia-like odor. Hydrazine is highly toxic and dangerously unstable unless handled in solution. Approximately 260,000 tons are manufactured annually...
to give allylic alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s. It can be used to synthesize carenol compounds.
Dupuy has developed an improved procedure.
Reaction mechanism
The mechanismReaction mechanism
In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs.Although only the net chemical change is directly observable for most chemical reactions, experiments can often be designed that suggest the possible sequence of steps in...
of the Wharton reaction begins with reaction of the ketone (1) with hydrazine to form a hydrazone
Hydrazone
Hydrazones are a class of organic compounds with the structure R1R2C=NNH2. They are related to ketones and aldehydes by the replacement of the oxygen with the NNH2 functional group...
(2). Rearrangement of the hydrazone gives intermediate 3, which can decompose giving off nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
gas forming the desired product 4. Stork et al. have investigated the mechanism of the final decomposition and found that it can proceed by an ionic mechanism or a radical mechanism depending on reaction temperature, solvent used, and structure of intermediate 3.
Notice that the alcohol retains the configuration of the starting epoxide. The reaction is named after Peter Stanley Wharton.