The reaction of an optically active trans-2-bromocyclohexanol with concentrated HBr solution results in optically inactive product trans-1,2-dibromocyclohexane (racemic). Show a mechanism showing how the reaction proceeds seemingly with complete retention of configuration, but actually with racemization. [Hint: Refer to the mechanism of the reaction when cyclohexene reacts with Br₂ in water to form trans-2-bromocyclohexanol.]