Question

What product(s) are expected in the ethoxide-promoted β-elimination reaction of 2-bromo-2,3-dimethylbutane? Omit ions, salts, and ethanol from your response.

Answer 1

There are two possible products from this elimination: 
-2,3-dimethylbut-1-ene 
-2,3-dimethylbut-2-ene 

As the base is relatively unhindered, the reaction will form the Saytzeff product as the major product. The Saytzeff product is the most substituted alkene which is more stable due to hyperconjugation. In this reaction the Saytzeff product is 2,3-dimethylbut-2-ene.