3- Methyl butanol

Except for the biochemical example just cited the stractures of all of the alcohols m Section 5 9 (including those m Problem 5 13) were such that each one could give only a single alkene by p elimination What about ehmmahon m alcohols such as 2 methyl 2 butanol m which dehydration can occur in two different directions to give alkenes that are conshtutional iso mers Here a double bond can be generated between C 1 and C 2 or between C 2 and C 3 Both processes occur but not nearly to the same extent Under the usual reachon con dihons 2 methyl 2 butene is the major product and 2 methyl 1 butene the minor one... 

There is a strong similarity between the mechanism shown m Eigure 5 12 and the one shown for alcohol dehydration m Eigure 5 6 The mam difference between the dehy dration of 2 methyl 2 butanol and the dehydrohalogenation of 2 bromo 2 methylbutane IS the source of the carbocation When the alcohol is the substrate it is the correspond mg alkyloxonmm ion that dissociates to form the carbocation The alkyl halide ionizes directly to the carbocation... 

Additional evidence for carbocation intermediates in certain nucleophilic substitutions comes from observing rearrangements of the kind normally associated with such species For example hydrolysis of the secondary alkyl bromide 2 bromo 3 methylbutane yields the rearranged tertiary alcohol 2 methyl 2 butanol as the only substitution product... 

Three of the most intense peaks in the mass spectrum of ] 2 methyl 2 butanol appear at m/z 59 70 and 73 Explain the origin of these peaks J... 

Properties 1-Pentanol 2-Pentanol 3-Pentanol 2-Methyl-1 -butanol 3-Methyl-l -butanol 2-Methyl-2 -butanol 3-Methyl-2 -butanol 2,2-Dimeth5i -1-propanol... 

Like the lower alcohols, amyl alcohols are completely miscible with numerous organic solvents and are excellent solvents for nitrocellulose, resia lacquers, higher esters, and various natural and synthetic gums and resius. However, iu contrast to the lower alcohols, they are only slightly soluble iu water. Only 2-methyl-2-butanol exhibits significant water solubiUty. As associated Hquids, amyl alcohols form a2eotropes with water and//or a variety of organic compounds (Table 3). 

Fig. 1. Viscosities of amyl alcohols compared with 1-butanol and 1-hexanol (15). a, 1-butanol b, 2-methyl-2-butanol c, 1-pentanol d, 2-methyl-1-butanol ...

AH eight amyl alcohol isomers are available from fine chemical supply firms in the United States. Five of them, 1-pentanol, 2-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol (/ fZ-amyl alcohols) are available in bulk in the United States in Europe all but neopentyl alcohol are produced (148,149). 

The submitters purchased 2-chloro-2-methylbutane from Eastman Kodak Company. The checkers prepared the halide as follows. A separatory funnel was charged with 21.5 mL (0.2 mol) of 2-methyl-2-butanol and IQO mL of coned hydrochloric acid. The mixture was shaken vigorously with periodic venting for 10 min. The layers were separated and the 2-chloro-2-methylbutane layer (upper) was washed several times with equal volumes of cold water. The product was dried over calcium chloride and distilled, bp 85 C. 

Some alcohols that have been converted into the corresponding fluorides by reactions with diethyldminosulfur trifluoride include 1-octanol, 2-methyl-2-butanol, isobutyl alcohol, cyclooctanol, ethylene glycol, crotyl alcohol, 2-phenylethanol, 2-bromoethanol, ethyl lactate, and ethyl a-hydrox3maphthaleneacetate. ... 

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