Two different alkenes are obtained in the E2 elimination reaction between 2-chloro-3-phenylbutane and sodium methoxide. The major product is the Zaitsev product.


(i) When one pure stereoisomer of 2-chloro-3-phenylbutane reacts, only one pure stereoisomer of the major product is obtained. For example, the product obtained when (2R,3R)-2-chloro-3-phenylbutane reacts is the stereoisomer with the methyl groups cis. Explain the reason behind this stereospecificity using the Newman projection of the transition state.
(ii) Predict the major product of elimination of (2S,3R)-2-chloro-3-phenylbutane using the Newman projection of the transition state.
(iii) By taking into account the results in part (i), predict the major product from the elimination of (2S,3S)-2-chloro-3-phenylbutane.