Penta-2,3-dienedioic acid

It was the first allene to be synthesized, in 1887, but the structure of it was thought to be a propyne core instead of an allene.

The correct structural isomeric identity was not determined until 1954.

[1] A diterpene, chemical name (4aR,5S,6R,8aR)-5-[(Z)-4-carboxy-3-methylbut-3-enyl]-5,6,8a-trimethyl-3,4,4a,6,7,8-hexahydronaphthalene-1-carboxylic acid (CID 6444268 from PubChem), is also called glutinic acid.

Some database entries for "glutinic acid" incorrectly identify it as this diterpene rather than the allene meaning in the underlying publications.

This article about an organic compound is a stub.