CC BY 2.0 UKPeppel, TimSonneck, MarcelSpannenberg, AnkeWohlrab, Sebastian2022-06-272022-06-272015https://oa.tib.eu/renate/handle/123456789/9284https://doi.org/10.34657/8322The mol­ecule of the title compound, C5H8O2, a low-melting [alpha],[beta]-unsaturated carb­oxy­lic acid, is essentially planar [maximum displacement = 0.0239 (13) Å]. In the crystal, mol­ecules are linked into centrosymmetric dimers via pairs of O-H...O hydrogen bonds.enghttps://creativecommons.org/licenses/by/2.0/uk/530Crystal structureDimerHydrogen bondUnsaturated carboxylic acidArticle