F l-Chloro-3-methylbutane

Carbon tetrachloride, 0322 Carbon tetrafluoride, 0349 Carbon tetraiodide, 0525 f 1-Chlorobutane, 1637 f 2-Chlorobutane, 1638 f Chlorocyclopentane, 1923 f l-Chloro-l,l-dilluoroethane, 0731 Chlorodilluoromethane, 0369 f Chloroethane, 0848 Chloroform, 0372 f Chloromethane, 0432 f l-Chloro-3-methylbutane, 1986 f 2-Chloro-2-methylbutane, 1987 f Chloromethyl ethyl ether, 1246 f Chloromethyl methyl ether, 0850 f l-Chloro-2-methylpropane, 1639 f 2-Chloro-2-methylpropane, 1640 f 1-Chloropentane, 1988 f 1-Chloropropane, 1243 f 2-Chloropropane, 1244 f l-Chloro-3,3,3-trifluoropropane, 1127 1,2-Dibromoethane, 0785 Dibromomethane, 0395... 

Problem 4.28 Give topological structural formulas for (a) propane, (b) butane, (c) isobutane, (d) 2,2-dimethyl-propane, (e) 2,3-dimethylbutane, (f) 3-ethylpentane, (g) l-chloro-3-methylbutane, (h) 2,3-dichloro-2-methylpentane, ( ) 2-chloro-2,4-trimethylpentane. "4... 

This result confirmed the earlier work of Whitmore, F. C. Johnston, F. /. Am. Chem. Soc. 1933, 55,5020, who had found that the addition of HCl to 3-methyl-l-butene without solvent, in a sealed reaction tube for 7 weeks, gave both 2-chloro-3-methylbutane and 2-chloro-2-methylbutane. This result contradicted the suggestion of earlier investigators that the 3° alkyl halide was formed by rearrangement of the 2° alkyl halide formed from the addition reaction. Hammond, G. S. Collins, C. H. /. Am. Chem. Soc. 1960, 82, 4323 found that addition of HCl to 1,2-dimethylcyclopentene produced Tchloro-frans-l,2-dimethylcyclopentane as the major (perhaps only) addition product, but it isomerized to l-chloro-c/s-l,2-dimethylcyclopentane. 

One of the best pieces of evidence supporting the carbocation mechanism for the electrophilic addition reaction was discovered during the 1930s by F. C. Whitmore of the Pennsylvania State University, who found that stmctural rearrangements often occur during the reaction of HX with an alkene. For example, reaction of HCl with 3-methyl-l-butene yields a substantial amount of 2-chloro-2-methyl-butane in addition to the "expected" product, 2-chloro-3-methylbutane. 

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