The Japp-Maitland condensation is an organic reaction

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,...

 and a type of Aldol reaction

Aldol reaction

The aldol reaction is a powerful means of forming carbon–carbon bonds in organic chemistry.Discovered independently by Charles-Adolphe Wurtz and Alexander Porfyrevich Borodin in 1872, the reaction combines two carbonyl compounds to form a new β-hydroxy carbonyl compound...

 and a tandem reaction. In a reaction between the 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...

 2-pentanone

2-Pentanone

Pentan-2-one or 2-pentanone or methyl propyl ketone is a colorless liquid ketone with an odor resembling that of acetone. Its formula is C5H10O. It is sometimes used in very small amounts as a flavoring food additive. Two other ketones, 3-pentanone and methyl isopropyl ketone are isomers of...

 and the aldehyde

Aldehyde

An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....

 benzaldehyde

Benzaldehyde

Benzaldehyde is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful. This colorless liquid has a characteristic pleasant almond-like odor...

 catalyzed

Catalysis

Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....

 by base

Base (chemistry)

For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...

 the bis Aldol adduct is formed first. The second step is a ring-closing reaction when one hydroxyl

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....

 group displaces the other in a nucleophilic substitution

Nucleophilic substitution

In organic and inorganic chemistry, nucleophilic substitution is a fundamental class of reactions in which an electron nucleophile selectively bonds with or attacks the positive or partially positive charge of an atom or a group of atoms called the leaving group; the positive or partially positive...

 forming a oxo-tetrahydropyran

Tetrahydropyran

Tetrahydropyran is the organic compound consisting of a saturated six-membered ring containing five carbon atoms and one oxygen atom. The compound is a colourless volatile liquid, but is obscure. Derivatives of tetrahydropyran are, however, more common. Tetrahydropyranyl ethers derived from the...

.

The reaction was first described by Francis Robert Japp

Francis Robert Japp

Francis Robert Japp was a British chemist who discovered the Japp-Klingemann reaction in 1887.He was born in Dundee, Scotland, the son of James Japp, a minister of the Catholic Apostolic Church. He graduated from St Andrews with an M.A. in 1868 and entered the University of Edinburgh as a student...

  and William Maitland in 1904.

The Japp-Maitland reaction is of some importance to synthetic organic chemistry for example as part of the synthesis of biomolecule

Biomolecule

A biomolecule is any molecule that is produced by a living organism, including large polymeric molecules such as proteins, polysaccharides, lipids, and nucleic acids as well as small molecules such as primary metabolites, secondary metabolites, and natural products...

centrolobine :