2,3-Epoxybutane

2,3-Epoxybutane is an organic compound with the formula CH₃CH(O)CHCH₃. It is an epoxide. The compound exists as three stereoisomers, a pair of enantiomers and the meso isomer. All are colorless liquids.

2,3-Epoxybutane

Names
Preferred IUPAC name 2,3-Dimethyloxirane
Other names 2,3-Butyleneoxide, 2,3-Buteneoxide
Identifiers
CAS Number	3266-23-7 meso or cis: 1758-33-4 S,S: 21490-63-1 R,R: 1758-32-3
3D model (JSmol)	Interactive image meso or cis: Interactive image S,S: Interactive image R,R: Interactive image
ECHA InfoCard	100.019.889
EC Number	221-877-8 meso or cis: 244-406-8 R,R: 244-406-8
PubChem CID	18632 meso or cis: 92162 S,S: 30664 R,R: 6432237
UN number	3271
CompTox Dashboard (EPA)	DTXSID5025239
InChI InChI=1S/C4H8O/c1-3-4(2)5-3/h3-4H,1-2H3 Key: PQXKWPLDPFFDJP-UHFFFAOYSA-N meso or cis: InChI=1S/C4H8O/c1-3-4(2)5-3/h3-4H,1-2H3/t3-,4+ Key: PQXKWPLDPFFDJP-ZXZARUISSA-N S,S: InChI=1S/C4H8O/c1-3-4(2)5-3/h3-4H,1-2H3/t3-,4-/m0/s1 Key: PQXKWPLDPFFDJP-IMJSIDKUSA-N R,R: InChI=1S/C4H8O/c1-3-4(2)5-3/h3-4H,1-2H3/t3-,4-/m1/s1 Key: PQXKWPLDPFFDJP-QWWZWVQMSA-N
SMILES CC1C(O1)C meso or cis: C[C@@H]1[C@@H](O1)C S,S: C[C@H]1[C@@H](O1)C R,R: C[C@@H]1[C@H](O1)C
Properties
Chemical formula	C4H8O
Molar mass	72.107 g·mol−1
Appearance	colorless liquid
Density	0.837 g·cm−3
Boiling point	64–78 °C (147–172 °F; 337–351 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation and reactions

2,3-Epoxybutane is prepared from 2-butene via the chlorohydrin:

CH₃CH=CHCH₃ + HOCl → CH₃CH(OH)CH(Cl)CH₃

CH₃CH(OH)CH(Cl)CH₃ → CH₃CH(O)CHCH₃ + HCl

A common reaction is its hydration to 2,3-butanediol. Many such ring-opening reactions have been reported.