Isoprenol
Structural formula of isoprenol
Ball-and-stick model of prenol
Names
Preferred IUPAC name
3-Methylbut-3-en-1-ol
Other names
3-Methyl-3-buten-1-ol
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.011.009 Edit this at Wikidata
EC Number
  • 212-110-8
UNII
  • InChI=1S/C5H10O/c1-5(2)3-4-6/h6H,1,3-4H2,2H3 checkY
    Key: CPJRRXSHAYUTGL-UHFFFAOYSA-N checkY
  • InChI=1/C5H10O/c1-5(2)3-4-6/h6H,1,3-4H2,2H3
  • OCCC(=C)C
Properties[1]
C5H10O
Molar mass 86.132 g/mol
Density 0.853 g/cm3
Boiling point 130 to 132 °C (266 to 270 °F; 403 to 405 K)
1.433
Hazards[2]
GHS labelling:
Flam. Liq. 3Eye Irrit. 2
Warning
H226, H319
P210, P233, P240, P241, P242, P243, P264, P280, P303+P361+P353, P305+P351+P338, P337+P313, P370+P378, P403+P235, P501
Flash point 36 °C (97 °F; 309 K)[note 1]
Related compounds
Related compounds
 Prenol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Isoprenol, also known as 3-methylbut-3-en-1-ol, is a hemiterpene alcohol. It is produced industrially as an intermediate to 3-methylbut-2-en-1-ol (prenol): global production in 2001 can be estimated as 6–13 thousand tons.[3]

Isoprenol is produced by the reaction between isobutene (2-methylpropene) and formaldehyde.

The reaction of isobutene with formaldehyde to give isoprenol, the first step in the industrial manufacture of prenol.
The reaction of isobutene with formaldehyde to give isoprenol, the first step in the industrial manufacture of prenol.

The thermodynamically preferred prenol with the more substituted double bond cannot be directly formed in the above reaction, but is produced via a subsequent isomerisation:

The isomerization of isoprenol to prenol, the second step in the industrial manufacture of prenol.
The isomerization of isoprenol to prenol, the second step in the industrial manufacture of prenol.

This isomerisation reaction is catalyzed by any species which can form an allyl complex without excessive hydrogenation of the substrate, for example poisoned palladium catalysts.[4]

Notes

  1. ^ Sigma-Aldrich Co. gives a value for the flash point of isoprenol of 42 °C (108 °F). The difference in the two values does not alter the safety classification of isoprenol as a category 3 flammable liquid under the GHS; but the lower value quoted here (from the New Zealand Environmental Risk Management Authority) would make it a class IC flammable liquid instead of a class II combustible liquid under the U.S. OSHA classification (29 C.F.R § 1910.106), and F3 rather than F2 under the NFPA 704 standard.

References

  1. ^ Sigma-Aldrich Co., 3-Methyl-3-buten-1-ol. Retrieved on 2009-08-31..
  2. ^ HSNO Chemical Classification Information Database, New Zealand Environmental Risk Management Authority, retrieved 2009-08-31.
  3. ^ 3-Methyl-2-buten-1-ol (PDF), SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, May 2005. Major produce in a world is BASF(Germany) and Kuraray(Japan).
  4. ^ See, e.g., Kogan, S. B.; Kaliya, M.; Froumin, N. (2006), "Liquid phase isomerization of isoprenol into prenol in hydrogen environment", Appl. Catal. A: Gen., 297 (2): 231–36, doi:10.1016/j.apcata.2005.09.010.
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