Diols

Overview

Compounds containing two alcohol groups on adjacent carbons.

Vicinal diols form when an alkene is oxidised with cold, dilute manganate(VII) under slightly alkaline conditions. Hot, concentrated acidified conditions instead promote oxidative cleavage of the double bond.

Identifiers

Functional group

C(OH)-C(OH)

Also known as

glycols, vicinal diols, dihydroxyalkanes

Related compounds

• Ethylene glycol

  A two-carbon diol that supplies the alcohol groups used to make PET.

• Propane-1,2-diol

  Propane-1,2-diol is an organic compound with the molecular formula C3H8O2.

• L-Tartaric acid

  L-Tartaric acid is an organic compound with the molecular formula C4H6O6.

Connected reactions

• Dihydroxylation: Alkenes → Diols

  Cold, dilute manganate(VII) oxidises an alkene to a vicinal diol without the oxidative cleavage associated with stronger conditions.

• Polyester formation co reactant: Diols → Polyesters

  Diols condense with dicarboxylic acids to form polyesters.

• Epoxide hydrolysis: Epoxides → Diols

  Protonation activates the strained ring toward attack by water. Backside attack breaks one C-O bond; proton transfer leaves hydroxyl groups on adjacent carbons, with an anti relationship when ring geometry makes that distinction meaningful.

References

1. Polyesters: manufacture and usesChemical Industry Education Centre, University of York
2. PubChem Compound Summary: Propane-1,2-diol (CID 1030)National Center for Biotechnology Information · PubChem

   Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

3. PubChem Compound Summary: L-Tartaric acid (CID 444305)National Center for Biotechnology Information · PubChem

   Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.