Octanol is a straight chain fatty alcohol

Fatty alcohol

Fatty alcohols are aliphatic alcohols consisting of a chain of 8 to 22 carbon atoms. Fatty alcohols usually have even number of carbon atoms and a single alcohol group attached to the terminal carbon. Some are unsaturated and some are branched...

 with eight carbon

Carbon

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

 atom

Atom

The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...

s and the molecular formula CH₃(CH₂)₇OH. Although the term octanol usually refers exclusively to the primary alcohol

Primary alcohol

A primary alcohol is an alcohol which has the hydroxyl radical connected to a primary carbon. It can also be defined as a molecule containing a “–CH2OH” group.Examples include ethanol and butanol....

 1-octanol, there are other less common isomers of octanol such as the secondary alcohols 2-octanol, 3-octanol and 4-octanol.

Octanol occurs naturally in the form of ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

s in some essential oils. The primary use of octanol is in the manufacture of various esters (both synthetic and naturally occurring), such as octyl acetate

Octyl acetate

Octyl acetate, or octyl ethanoate, is an ester that is formed from octanol and acetic acid.Octyl acetate can be synthesized by a condensation reaction:-Use:...

, which are used in perfumery and flavors. Other uses include experimental medical applications utilizing octanol to control Essential Tremor and other types of involuntary neurological tremors.

Preparation

Octanol is produced industrially by the oligomerization of ethylene

Ethylene

Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

 using triethylaluminium

Triethylaluminium

Triethylaluminium is an organoaluminium compound. This volatile, colorless liquid is highly pyrophoric, igniting immediately upon exposure to air. It is normally stored in stainless steel containers either as a pure liquid or as a solution in hydrocarbon solvents such as hexane, heptane, or ...

 followed by oxidation of the alkylaluminium products

Organoaluminium

Organoaluminium chemistry is the study of compounds containing bonds between carbon and aluminium bond. It is one of the major themes within organometallic chemistry. Illustrative organoaluminium compounds are the dimer trimethylaluminium, the monomer triisobutylaluminium, and the...

. 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

Distillation

Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....

.

Water/octanol partitioning

Octanol and water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 are immiscible. The distribution of a compound between water and octanol is used to calculate the partition coefficient

Partition coefficient

In chemistry and the pharmaceutical sciences, a partition- or distribution coefficient is the ratio of concentrations of a compound in the two phases of a mixture of two immiscible solvents at equilibrium. The terms "gas/liquid partition coefficient" and "air/water partition coefficient" are...

 '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

Cytosol

The cytosol or intracellular fluid is the liquid found inside cells, that is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into compartments....

 and lipid

Lipid

Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...

 membrane

Biological membrane

A biological membrane or biomembrane is an enclosing or separatingmembrane that acts as a selective barrier, within or around a cell. It consists of a lipid bilayer with embedded proteins that may constitute close to 50% of membrane content...

s of living systems.

Many dermal absorption models consider the stratum corneum

Stratum corneum

The stratum corneum is the outermost layer of the epidermis, consisting of dead cells that lack nuclei and organelles. The purpose of the stratum corneum is to form a barrier to protect underlying tissue from infection, dehydration, chemicals and mechanical stress...

/ water partition coefficient to be well approximated by a function of the water/ octanol partition coefficient of the form:


Where a and b are constants, is the stratum corneum/ water partition coefficient, and is the water/ octanol partition coefficient. The values of a and b vary between papers, but Cleek & Bunge have reported the values a=0, b=0.74.