4-Hydroxy-3,5-Dimethoxybenzaldehyde (Syringaldehyde)

Molecules of syringaldehyde, C9H10O4, are connected by intermolecular O-H...O [H...O = 2.05 Angstrom and O...O = 2.713 (2) Angstrom] hydrogen bonds between the 4-hydroxy and 1-aldehyde functions into infinite linear chains. The 4-hydroxy H atoms also participate in an intramolecular O-H...O [H...O = 2.22 Angstrom and O...O = 2.662 (2) Angstrom] interaction with a neighbouring methoxy O atom.