1,3-Dioxane

1,3-Dioxane or m-dioxane is an organic compound with the molecular formula (CH₂)₄O₂. It is a saturated six-membered heterocycle with two oxygen atoms in place of carbon atoms at the 1- and 3- positions. 1,4-Dioxane, which is of greater commercial value, is an isomer. Both dioxanes are colorless liquids.^[1]

1,3-Dioxane

Names
Preferred IUPAC name 1,3-Dioxane
Other names Formaldehyde trimethylene acetal
Identifiers
CAS Number	505-22-6
3D model (JSmol)	Interactive image
Beilstein Reference	102532
ChEBI	CHEBI:46924
ChemSpider	10018
ECHA InfoCard	100.007.278
EC Number	208-005-1
PubChem CID	10450
RTECS number	JG8224000
UNII	B2C8M17I09
UN number	1165
CompTox Dashboard (EPA)	DTXSID3025174
InChI InChI=1S/C4H8O2/c1-2-5-4-6-3-1/h1-4H2 Key: VDFVNEFVBPFDSB-UHFFFAOYSA-N
SMILES C1COCOC1
Properties
Chemical formula	C4H8O2
Molar mass	88.106 g·mol−1
Appearance	colorless liquid
Melting point	−42 °C (−44 °F; 231 K)
Boiling point	103 °C (217 °F; 376 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H302, H312, H315, H332
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+P312, P302+P352, P303+P361+P353, P304+P312, P304+P340, P312, P321, P322, P330, P332+P313, P362, P363, P370+P378, P403+P235, P501
Flash point	2 °C (36 °F; 275 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 derivatives

The parent 1,3-dioxane is prepared by the reaction of formaldehyde and 1,3-propanediol in the presence of Brönsted or Lewis acid catalysts.

Substituted derivatives can be used as protecting groups for carbonyl compounds. are prepared from the reaction between a ketone or an aldehyde with 1,3-diols. ^[2] They can also be produced by the Prins reaction.^[3]

Related compounds

1,3-Dioxolanes are five-membered rings with the formula (CH₂)₃O₂.

See also

• 1,2-Dioxane
• 1,4-Dioxane
• Dithiane

References

1. Surprenant, Kenneth S. (2000). "Dioxane". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a08_545. ISBN 3527306730.
2. Greene, Theodora W.; Wuts, Peter G. M. (1999). "1,3-Dioxanes, 1,3-Dioxolanes". Greene's Protective Groups in Organic Synthesis (3rd ed.). Wiley-Interscience. pp. 308–322, 724–727. ISBN 9780471160199. Archived from the original on December 7, 2016. Retrieved June 12, 2020.
3. Shriner, R. L.; Ruby, Philip R. (1953). "4-Phenyl-m-Dioxane". Organic Syntheses. 33: 72. doi:10.15227/orgsyn.033.0072.