Amyl alcohol
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2008-06-12T17:32:14Z
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'''Amyl alcohol''' is an [[organic compound]] with the formula C<sub>5</sub>H<sub>11</sub>OH. All eight [[isomer]]s of [[amyl]] [[alcohol]] are known:
{| border="1" cellpadding="2" cellspacing="0"
|+'''Isomers of amyl alcohol'''
|-
! name || formula || [[Alcohol#Structure|alcohol structure]] || [[Systematic name|IUPAC Name]]
|-
| normal amyl alcohol
| [[Image:Pentan-1-ol-2D-skeletal.png|150px]]
| primary
| [[1-pentanol]]
|-
| isobutyl carbinol<br>or isoamyl alcohol<br>or isopentyl alcohol
| [[Image:Isopentanol-2D-skeletal.png|120px]]
| primary
| [[3-methyl-1-butanol]]
|-
| active amyl alcohol
| [[Image:2-methylbutan-1-ol-2D-skeletal.png|120px]]
| primary
| [[2-methyl-1-butanol]]
|-
| tertiary butyl carbinol<br>or neopentyl alcohol
| [[Image:Neopentyl-alcohol-2D-skeletal.png|100px]]
| primary
| [[2,2-dimethyl-1-propanol]]
|-
| diethyl carbinol
| [[Image:Pentan-3-ol-2D-skeletal.png|100px]]
| secondary
| [[3-pentanol]]
|-
| methyl (n) propyl carbinol
| [[Image:Pentan-2-ol-2D-skeletal.png|100px]]
| secondary
| [[2-pentanol]]
|-
| methyl isopropyl carbinol
| [[Image:3-methylbutan-2-ol-2D-skeletal.png|80px]]
| secondary
| [[3-methyl-2-butanol]]
|-
| dimethyl ethyl carbinol<br>or tertiary amyl alcohol
| [[Image:Tert-pentyl-alcohol-2D-skeletal.png|100px]]
| tertiary
| [[2-methyl-2-butanol]]
|}
Three of these alcohols, active amyl alcohol, methyl (n) propyl carbinol, and methyl isopropyl carbinol, are [[optical isomerism|optically active]], as they contain an asymmetric carbon atom.
The most important is isobutyl carbinol, this being the chief constituent of fermentation amyl alcohol, and consequently a constituent of [[fusel oil]]. It can be separated from fusel oil by shaking with strong [[brine]] solution, separating the oily layer from the brine layer and [[distillation|distilling]] it, the portion boiling between 125 and 140 °C. being collected. For further purification it may be shaken with hot [[lime water]], the oily layer separated, dried with [[calcium chloride]] and fractionated, the fraction boiling between 128 and 132 °C only being collected. It may be synthesized from [[isobutanol]] by conversion into isovaleraldehyde, which is subsequently reduced to isobutyl carbinol by means of [[sodium amalgam]].
It is a colourless liquid of density 0.8247 g/cm³ (0 °C), boiling at 131.6 °C, slightly soluble in water, easily soluble in organic solvents. It possesses a characteristic strong smell and a sharp burning taste. When pure, it is nontoxic, while the impure product is toxic. On passing its vapour through a red-hot tube, it decomposes with production of [[acetylene]], [[ethylene]], [[propylene]], and other compounds. It is [[oxidation|oxidized]] by [[chromic acid]] to isovaleraldehyde, and it forms crystalline addition compounds with [[calcium chloride]] and [[tin(IV) chloride]].
The other amyl alcohols may be obtained synthetically. Of these, tertiary butyl carbinol has been the most difficult to obtain, its synthesis having first been reported in [[1891]], by L. Tissier (''Comptes Rendus'', 1891, 112, p. 1065) by the reduction of a mixture of trimethyl acetic acid and trimethylacetyl chloride with sodium amalgam. It is a solid that melts at 48 to 50 °C and boils at 112.3 °C.
==References==
*{{1911}}
==External links==
[[Category:Alcohols]]
[[de:Pentanole]]
[[fr:Alcool amylique]]
[[ja:ペンチルアルコール]]
[[la:Pentanol]]
[[lv:Amilspirts]]
[[pt:Álcool amílico]]
[[ru:Амиловый спирт]]
[[tr:Amil alkol]]