Tert-Butyl bromide 2-methylpropene

Methylpropene tert-Butyl bromide Isobutyl bromide... 

The reaction of HBr with 2-methylpropene produces only tert-butyl bromide. 

Addition of HBr to 2-methylpropene gives mainly tert-butyl bromide, because the product with the more stable carbocation intermediate always predominates in this type of reaction. 

The reaction of tert-butyl bromide with ethoxide ion, shown at the beginning of Section 9.2, resulted in the formation of 2-methylpropene in an E2 reaction. If ethoxide ion is not present in the reaction, E2 elimination is greatly slowed, and both substitution and elimination products are formed. 

Chapter 5 will describe elimination reactions and their mechanisms. In one example, heating tert-butyl bromide in ethanol gives the alkene 2-methylpropene by a two-step mechanism ... 

The El reaction involves the formation of a planar carbocation intermediate. Therefore, both syn and anti elimination can occur. If an elimination reaction removes two substituents from the same side of the C—C bond, the reaction is called a syn elimination. When the substituents are removed from opposite sides of the C—C bond, the reaction is called an anti elimination. Thus, depending on the substrates El reaction forms a mixture of cis (Z) and trans (E) products. For example, tert-hutyl bromide (3° alkyl halide) reacts with water to form 2-methylpropene, following an El mechanism. The reaction requires a good ionizing solvent and a weak base. When the carbocation is formed, SnI and El processes compete with each other, and often mixtures of elimination and substitution products occur. The reaction of t-butyl bromide and ethanol gives major product via El and minor product via SnI-... 

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