3 Methyl-2-butanol. physical properties

Commercial primary amyl alcohol is a mixture of 1-pentanol and 2-methyl-1-butanol, iu a ratio of ca 65 to 35 (available from Union Carbide Chemicals and Plastics Company Inc. iu other ratios upon request). Typical physical properties of this amyl alcohol mixture are Hsted iu Table 2 (17). 

Propylene oxide is a colorless, low hoiling (34.2°C) liquid. Table 1 lists general physical properties Table 2 provides equations for temperature variation on some thermodynamic functions. Vapor—liquid equilibrium data for binary mixtures of propylene oxide and other chemicals of commercial importance ate available. References for binary mixtures include 1,2-propanediol (14), water (7,8,15), 1,2-dichloropropane [78-87-5] (16), 2-propanol [67-63-0] (17), 2-methyl-2-pentene [625-27-4] (18), methyl formate [107-31-3] (19), acetaldehyde [75-07-0] (17), methanol [67-56-1] (20), ptopanal [123-38-6] (16), 1-phenylethanol [60-12-8] (21), and / /f-butanol [75-65-0] (22,23). 

With few exceptions, enantiomers cannot be separated through physical means. When in racemic mixtures, they have the same physical properties. Enantiomers have similar cliemi cal properties as well. The only chemical difference between a pair of enantiomers occurs in reactions with other chiral compounds. Thus resolution of a racemic mixture typically takes place through a reaction with another optically active reagent. Since living organisms usually produce only one of two possible enantiomers, many optically active reagents can be obtained from natural sources. For instance muscle tissue and (S)-<-)-2-methyl-l-butanol, from yeast fermentation. 

Optical Activity.—We come now, in the case of the isomeric alcohols, to a new and inost interesting example of isomerism. The five carbon alcohol 2-methyl butanol-i, differs from the other seven structurally isomeric amyl alcohols not only in structure, but also in other striking ways. Three different amyl alcohols are known all of which have the constitution of 2-methyl butanol-i. Two of these three are known as optically active all the other amyl alcohols being inactive. Certain substances either in the crystalline form, as in the case of quartz in solution, as in the case of sugar or in the liquid form, as in the case of the alcohol we are considering possess this physical property of optical activity. This property is shown by the fact that the compound has the power to turn or rotate the plane of vibration of a ray of light that has been polarized. 

What we are concerned with at this time is an explanation on chemical grounds of the important fact that three amyl alcohols or pentanolSf are known all of which possess the same structural formula viz., 2-methyl butanol-i and that one of these compounds is dextrorotatory another is levo-rotatory and the third one is inactive. These three are different individual compounds with practically the same physical properties other than optical. The inactive variety of 2-methyl butanol-1 differs, however, from the other seven structurally isomeric pentanols which are likewise inactiye not only in its structure but also in the fact that by means of certain reactions there may be obtained from it both the dextro-rotatory and the levo-rotatory compounds. In it, and in other inactive compounds of the same kind, there are present equivalent amounts of the two oppositely active compounds,... 

Enantiomers have identical physical properties, except for the direction of rotation of the plane of polarized light. The two 2-methyl-1-butanols, for example. 

Prepd by condensation of teri-pemanol or 2-methyl -3-butanol with phenol in the presence of aluminum chloride Huston, Hsieh, J. Am. Chem. Soc. 58, 439 (1936) Huston et al.. ibid. 67, 899 (1945). Physical properties Pardee, Wein-rich, lnd. Eng. Client. 36, 595 (1944). 

Commonly used water-immiscible solvents in industrial-scale processes include alcohols (isobutanol, -butanol), ketones (particularly methyl isobutyl ketone), acetates (butyl, ethyl, isopropyl), hydrocarbons (toluene, hexanes), and methylene chloride. These solvents are inexpensive, readily available, and exhibit physical properties of low viscosity and density significantly different from water. Common water-miscible solvents are the alcohols (particularly methanol). For laboratory-scale processes, the selection is greater since selection is not constrained by economics. Craig and Sogn (16) have prepared an extensive compilation of such solvents. 

Physical properties sec- Amyl alcohol tert-Amyl alcohol -Hexyl alcohol Cyclo- hexanol 2-Ethyl-1-butanol Methyl isobutyl carbinol 2-Ethyl- 1-hexanol -Octyl alcohol sec- Octyl alcohol Nonyl alcohol Decyl alcohol... 

Chemical Designations — Synonyms Fermentation amyl alcohol Fusel oil Iso-butylcarbinol Isopentyl alcohol 3-Methyl-l-butanol Potato-spirit oil Chemical Formula (CH3)2CHCH2CH20H. Observable Characteristics — Physical State (as shipped) Liquid Color Colorless Odor Mild odor alcoholic, non-residual. Physical and Chemical Properties — Physical State at 15"C and 1 atm. Liquid Molecular Weight 88.15 Boiling Point at 1 atm. 270, 132, 405 Freezing Point Not pertinent Critical Temperature 585, 307, 580 Critical Pressure Not pertinent Specific Gravity 0.81 at 20"C (liquid) Vapor (Gas) Specific Gravity Not pertinent Ratio of Specific Heats of Vapor (Gas) (est.) 1.062 Latent Heat of Vaporization 215.6, 119.8, 5.016 Heat of Combustion -16,200, -9,000, -376.8 ... 

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