Question

9. Treatment of (2R,3S)-2-chloro-3-methylpentane with potassium t-butoxide in t-butanol gives a single stereoisomer of 3-phenyl-2-butene. (15 pts) CI CH, | (CH, CƠ K, CH,CH=C-CH-CH, CHE (CH3),COH Draw the three possible Newman projections of the staggered conformations of (2R,3S)-2- chloro-3-methylpentane. Circle the one Newman projection with the conformation most suited for the elimination reaction. Conformation 2 Conformation 3 Conformation 1 Show the stereoisomer of the product expected from this elimination path.

Answer 1

CzC2 CH₂ CH 3 -CHZ a H H₃ H Conformation=1 Here BH' and ci remain in anti direction, So, suitable for elimination Rxn. for elimination, Conformation - 2 Stereo isomers of is suitable foroduct! CH₂ CH3 H , CHE -CH3 CH₂ CH₂