The compound shown (a menthane skeleton) is heated with sodium ethoxide in ethanol. Which structure is the major alkene?

The compound is neomenthyl chloride, in which chlorine is axial (cis to the isopropyl group) in the stable chair with the other two groups equatorial. The C-2 hydrogen, which carries the isopropyl group, is axial and anti to chlorine, as is the C-6 hydrogen. The Saytzeff product, the trisubstituted 3-menthene, therefore forms as the major alkene.