What are the major and minor products obtained in the reaction of (E)-3-methyl-2-pentene and HBr?

1 Answer
Jun 28, 2015

The major product by far is 3-bromo-3-methylpentane; there may be a small amount of 2-methyl-3-bromopentane.

Explanation:

The structure of (#E#)-3-methylpent-2-ene is

www.slcc-science.org

According to Markovnikov's rule, the #"H"^+# from #"HBr"# will add to #"C-2"# of the alkene and form a 3° carbocation at #"C-3"#.

The #"Br"^-# will add to #"C-3"# and form 3-bromo-3-methylpentane

enter image source here

There may be a small amount of product formed when the #"H"^+# adds to #"C-3"# of the alkene to form the less stable 2° carbocation at #"C-2"#.

The #"Br"^-# will then add to #"C-2"# and form 2-bromo-3-methylpentane.

enter image source here