C4H8O

C4H8O is the chemical formula for a family of organic compounds that contain four carbon atoms and one oxygen atom. With four carbons, the formula corresponds to a single degree of unsaturation, which in practice can arise from a ring or a carbonyl group. As a result, C4H8O encompasses several distinct structural classes, including aldehydes, ketones, ethers, epoxides, and cyclic alcohols.

Representative isomers include:

- Butanal (butyraldehyde), an aldehyde with the chain CH3-CH2-CH2-CHO.

- 2-Methylpropanal (isobutanal), an aldehyde with a branched skeleton.

- 2-Butanone (methyl ethyl ketone), a ketone with the carbonyl adjacent to two alkyl groups.

- Tetrahydrofuran (THF), a five-membered cyclic ether.

- 1,2-Epoxybutane (butylene oxide), an epoxide derived from a butene skeleton.

- Cyclobutanol, a saturated cyclic alcohol with a four-member ring.

Other isomers possible for C4H8O include additional cyclic ethers such as methyl-substituted oxetanes and related ring structures, as well as other cyclic or branched alcohols. The formula therefore represents a set of constitutional isomers rather than a single compound, each with its own properties and uses.

Applications and properties vary among the isomers. Some, like THF and 2-butanone, are widely used as solvents in chemical synthesis, while others serve as intermediates in flavorings, fragrances, or specialty chemicals. The diversity of C4H8O compounds reflects the broader range of small oxygen-containing organics that arise from four-carbon backbones.