Octanol

(Redirected from Octan-1-ol)
Octanol
Identifiers
CAS number 111-87-5
PubChem 957
ChemSpider 932
ChEMBL CHEMBL26215
Jmol-3D images Image 1
Properties
Molecular formula C8H18O
Molar mass 130.23 g mol−1
Density 0.824 g/cm3
Melting point

-16 °C, 257 K, 3 °F

Boiling point

195 °C, 468 K, 383 °F

Solubility in water Insoluble
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

The term Octanol usually refers to the isomer, octan-1-ol, with the molecular formula CH3(CH2)7OH. It is a fatty alcohol. Many other isomers are also known. Esters of octanol, such as octyl acetate, occur as components of essential oils. Octanol is manufactured for the synthesis of esters for use in perfumes and flavorings. It is used to model the partitioning of pharmaceutical products between water and the cytosol. Other uses include experimental medical procedures for controlling Essential Tremor and other types of involuntary neurological tremors.[1]

Preparation

Octanol is produced industrially by the oligomerization of ethylene using triethylaluminium followed by oxidation of the alkylaluminium products.[2] An idealized synthesis is shown:

Al(C2H5)3 + 9 C2H4 → Al(C8H17)3
Al(C8H17)3 + 3 O + 3 H2O → 3 HOC8H17 + Al(OH)3

The process generates a range of alcohols that are separated by distillation.

Water/octanol partitioning

Octanol and water are immiscible. The distribution of a compound between water and octanol is used to calculate the partition coefficient 'P' of that molecule (often expressed as its logarithm to the base 10, log P). Water/ octanol partitioning is a relatively good approximation of the partitioning between the cytosol and lipid membranes of living systems.[3]

Many dermal absorption models consider the stratum corneum/ water partition coefficient to be well approximated by a function of the water/ octanol partition coefficient of the form:[4]

$\log(K_{sc/w}) = a + b\log(K_{w/o})$

Where a and b are constants,$K_{sc/w}$ is the stratum corneum/ water partition coefficient, and$K_{w/o}$ is the water/ octanol partition coefficient. The values of a and b vary between papers, but Cleek & Bunge[5] have reported the values a=0, b=0.74.

References

1. ^ Bushara K. et al. (2004). "Pilot trial of 1-octanol in essential tremor". Neurology 62 (1): 122–124. PMID 14718713.
2. ^ Jürgen Falbe, Helmut Bahrmann, Wolfgang Lipps, Dieter Mayer "Alcohols, Aliphatic" in Ullmann's Encyclopedia of Chemical Technology Wiley-VCH Verlag; Weinheim, 2002. doi:10.1002/14356007.a01_279
3. ^ Schwarzenbach, Rene P.; Gschwend, Philip M.; Imboden, Dieter M. (2003). Environmental organic chemistry. John Wiley. ISBN 0-471-35053-2.
4. ^ McCarley KD, Bunge AL (2001). "Pharmacokinetic Models of Dermal Absorption". Journal of Pharmaceutical Sciences 90 (11): 1699–1719. doi:10.1002/jps.1120. PMID 11745728.
5. ^ Cleek RL, Bunge AL (1993). "A new method for estimating dermal absorption from chemical exposure. 1. General approach". Pharmaceutical Research 10 (4): 497–506. doi:10.1023/A:1018981515480. PMID 8483831.