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.
