Question

Problem IV The Elimination reaction allows the removal from a molecule of a Leaving group and a neighboring Hydrogen to generate a double bond. When that reaction is performed on a cyclohexane, the leaving group (Br in the example below, and the H must be Axial as shown below. Base When the reaction is performed on the two molecule below (A and B), it is found that the reaction works very well on molecule A but very slowly on molecule B. Propose an explanation for this observation.

Answer 1

Br Br write chair form Н Н A Bulky group is equatorial hence more stable conformation So the reaction is faster Br Br Н write chair form Н В Br ring flip Н Br More stable conformer. So the reaction is slower both groups are axial Hence this conformation is less stable.