One method to convert an alcohol into an alkyl iodide is by using triphenylphosphine and iodine. Provide a mechanism for the reaction below. (Hint: triphenylphosphine first acts as a nucleophile.)

Write a mechanism for the reaction of 2-methylbutan-2-ol with concentrated HCl goes by an S_N1 reaction.

What is the major product of the reaction shown below?

Determine the reagents needed for the following reaction to happen.

What is the mechanism for the following reaction?

1,3,4-trimethylcyclopentan-1-ol + HBr → 1-bromo-1,3,4-trimethylcyclopentane

When hexan-3-ol is treated with concentrated HBr solution, the reaction proceeds with partial racemization with excess inversion. Provide the possible mechanism accounting for racemization resulting in greater inversion than retention of configuration.

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.]