Amyl alcohol 3045 218895395 2008-06-12T17:32:14Z 168.212.177.181 '''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]]