Decahydroxycyclopentane

Decahydroxycyclopentane is an organic compound with formula C₅O₁₀H₁₀ or C₅(OH)₁₀. It is a fivefold geminal diol on a cyclopentane backbone.

The compound can be regarded as the fivefold hydrate of cyclopentanepentone. Indeed, the product referred to in the literature and trade as "cyclopentanepentone pentahydrate" (C₅O₅·5H₂O) is now believed to be the decahydroxycyclopentane.

The compound was synthetized by Heinrich Will in 1861, although for a long time it was believed to be a hydrate of C₅O₅. It can be prepared by oxidation of croconic acid C₅O₃(OH)₂ with nitric acid. It can be isolated as water-soluble colorless crystals that melt with dehydration at about 115 °C, and slowly decompose at about 160 °C.