Which of the Newman projections represents the lowest energy conformation of 2-bromobutane?
a) The staggered conformation with the bromine anti to one of the hydrogen atoms on the butane chain is usually the lowest energy conformation. This is because in this conformation, there is minimal steric hindrance between the bulky bromine atom and the hydrogen atoms.
b) The staggered conformation with the bromine gauche to one of the hydrogen atoms on the butane chain typically represents a higher energy conformation compared to option a) because of increased steric hindrance between the bromine atom and the nearby hydrogen atoms.
c) The eclipsed conformation where the bromine and one of the hydrogen atoms are directly in line typically represents a higher energy conformation due to torsional strain.
d) Another eclipsed conformation where the bromine and one of the methyl groups are directly in line also typically represents a higher energy conformation due to torsional strain.