Hooker reaction
Encyclopedia
In the Hooker reaction (1936) an alkyl chain in a certain naphthoquinone
(phenomenon first observed in the compound lapachol
) is reduced by one methylene
unit as carbon dioxide
in each potassium permanganate
oxidation.
Naphthoquinone
Naphthoquinone is a class of natural phenols based on the C6-C4 skeleton.1,4-Naphthoquinone can be viewed as derivatives of naphthalene through the replacement of two hydrogen atoms by two ketone groups....
(phenomenon first observed in the compound lapachol
Lapachol
Lapachol is a natural organic compound isolated from the lapacho tree . Chemically, it is a derivative of naphthoquinone, related to vitamin K....
) is reduced by one methylene
Methylene
Methylene is a chemical species in which a carbon atom is bonded to two hydrogen atoms. Three different possibilities present themselves:* the -CH2- substituent group: e.g., dichloromethane ....
unit as carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
in each potassium permanganate
Potassium permanganate
Potassium permanganate is an inorganic chemical compound with the formula KMnO4. It is a salt consisting of K+ and MnO4− ions. Formerly known as permanganate of potash or Condy's crystals, it is a strong oxidizing agent. It dissolves in water to give intensely purple solutions, the...
oxidation.
- Mechanistically oxidation causes ring-cleavage at the alkene group, extrusion of carbon dioxideCarbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
in decarboxylationDecarboxylationDecarboxylation is a chemical reaction that releases carbon dioxide . Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carbonation, the addition of CO2 to...
with subsequent ring-closure.