In summary, the conversation is about determining the reaction to a product with two stereocenters and determining the priority order for the hydrogens. The speaker is also trying to determine if the product will be an E1 or E2 elimination. The conversation ends with the expert explaining why an E1 elimination is more likely in this case.
You have two stereocenters there. Arrange them so that the hydrogens are dashed. Determine the priority order. Go from highest priority to lowest. Clockwise is R.
Are you trying to determine the product of this reaction? It's going to be an E1 elimination. I'll explain how I figured that out:
-Potassium t-butoxide is a strong base and a weak nucleophile, so nucleophilic substitution will be unlikely (and that is a competitive reaction with eliminations). This leaves you with two options: E1 or E2 elimination.
-E2 elimination is unlikely in a polar solvent (t-butanol).
-The substrate molecule has an allylic bromine. If the C-Br bond were to spontaneously break, the carbocation formed would have resonance stabilization. As such, a mechanism involving a carbocation is likely, especially considering that the solvent is polar and can stabilize the carbocation even more.