Question

On a separate sheet of paper, draw the two alternative chair conformations for the product formed by the addition of bromine to 4-tert-butylcyclohexene. The Gibbs free-energy differences between equatorial and axial substituents on a cyclohexane ring are 21 kJ/mol for tert-butyl, and 2.3 kJ/mol for bromine. Calculate the ratio of the two observed products at 46.0 °C using the following equation: The gas constant, R, is 8.314 J/K·mol. (Enter your answer to two significant figures.) Ratio: ____ to 1 Major to Minor

On a separate sheet of paper, draw the two alternative chair conformations for the product formed by the addition of bromine to 4-tert-butylcyclohexene. The Gibbs free-energy differences between equatorial and axial substituents on a cyclohexane ring are 21 kJ/mol for tert-butyl, and 2.3 kJ/mol for bromine. Calculate the ratio of the two observed products at 46.0 °C using the following equation: AGⓇ = -RT In Keq The gas constant, R, is 8.314 J/K mol. (Enter your answer to two significant figures.) Ratio: Major to 1 Minor Submit Answer Try Another Version 1 item attempt remaining

Answer 1

t- Bu at equitonial. Y filii 11 † t-Bu at axial * LC) (D) minor. major Bromine atoms are trans with respect to each other due to anti adition geometry. Out of abone four structure A, B, C, D, Only two structure obserted are A4D. S1 118

Energy diffinence betwen AfD j calculated as follows. The conformal energy diffinince based on axial us equito- nial t-butyl group is 21 kJ/mol and it will use intermidiate • value 2.3 kJ/mol for romine , Thus. total energy diffinenu betuun - A and is 21 kJ/mo! - (2x 2.3) kJ/mol = 16.4 kJ/mol. Now AG= - RT in Keq. 1 0 1 0 16.4 0 8.314 x 319 е 0 0 0 607 - 0.99383 - 0.994 major product y [A] and ratio. of minor to is 0.99. | | This major
Thus ration is. 99 to 1.