Chemistry - STEREO ISOMERISM Question with Solution | TestHub

IV is anti (Br-C-C-Br dihedral 180°) : no eclipsing, no gauche Br↔Br strain - lowest energy. I is gauche (staggered, but Br↔Br gauche steric strain) - next. III is partially eclipsed (two Br↔H eclipses and one H↔H eclipse). II is fully eclipsed with Br eclipsing Br - the highest energy. Hence IV $<$ I $<$ III $<$ II.