The Wieland-Gumlich aldehyde is an indoline

Indoline

Indoline is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. The compound is based on the indole structure, but the 2-3 bond is saturated. by oxidation/dehydrogenation it can be...

 derived from strychnine

Strychnine

Strychnine is a highly toxic , colorless crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine causes muscular convulsions and eventually death through asphyxia or sheer exhaustion...

. This compound is of some commercial interest as a chemical intermediate. It was first synthesized in 1932 by Wieland

Heinrich Otto Wieland

Heinrich Otto Wieland was a German chemist. He won the 1927 Nobel Prize in Chemistry for his research into the bile acids. In 1901 Wieland received his doctorate at the University of Munich while studying under Johannes Thiele...

 and Gumlich in 4 steps from strychnine

Strychnine

Strychnine is a highly toxic , colorless crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine causes muscular convulsions and eventually death through asphyxia or sheer exhaustion...

 (1). This degradation study was part of an attempt to elucidate the chemical structure of strychnine.

This degradation takes place through formation of oxime

Oxime

An oxime is a chemical compound belonging to the imines, with the general formula R1R2C=NOH, where R1 is an organic side chain and R2 may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substituted oximes form a closely related family of compounds...

 2 using amyl nitrite

Amyl nitrite

Amyl nitrite is the chemical compound with the formula C5H11ONO. A variety of isomers are known, but they all feature an amyl group attached to the nitrito functional group. The alkyl group is unreactive and the chemical and biological properties are mainly due to the nitrite group...

, carbamic acid

Carbamic acid

Carbamic acid is a compound that is unstable under normal circumstances. It is technically the simplest amino acid, though its instability allows glycine to assume this title. Its importance is due more to its relevance in identifying the names of larger compounds...

 3 through a Beckmann fragmentation using (thionyl chloride

Thionyl chloride

Thionyl chloride is an inorganic compound with the formula SOCl2. It is a reactive chemical reagent used in chlorination reactions. It is a colorless, distillable liquid at room temperature and pressure that decomposes above 140 °C. Thionyl chloride is sometimes confused with sulfuryl...

), through a decarboxylation

Decarboxylation

Decarboxylation 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...

 to nitrile

Nitrile

A nitrile is any organic compound that has a -C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, one example being super glue .Inorganic compounds containing the -C≡N group are not called...

 4 and through a nucleophilic displacement  with barium hydroxide

Barium hydroxide

Barium hydroxide is the chemical compound with the formula Ba2. Also known as baryta, it is one of the principal compounds of barium. The white granular monohydrate is the usual commercial form.-Preparation:...

 to 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....

 5. Its hemiacetal

Hemiacetal

Hemiacetals and hemiketals are compounds that are derived from aldehydes and ketones respectively. The Greek word hèmi means half...

 gives the Wieland-Gumlich aldehyde (6).

The Wieland-Gumlich aldehyde reverts back to strychnine in a single reaction using malonic acid

Malonic acid

Malonic acid is a dicarboxylic acid with structure CH22. The ionised form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's ethyl ester...

, acetic anhydride

Acetic anhydride

Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula 2O. Commonly abbreviated Ac2O, it is the simplest isolatable acid anhydride and is a widely used reagent in organic synthesis...

 and sodium acetate

Sodium acetate

Sodium acetate, CH3COONa, also abbreviated NaOAc, also sodium ethanoate, is the sodium salt of acetic acid. This colourless salt has a wide range of uses.-Industrial:...

 in acetic acid

Acetic acid

Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

.

The Wieland-Gumlich aldehyde has been used in the industrial synthesis of alcuronium chloride via dimerization.