In most instances hydrolysis of an alkylhalide is catalyzed by hydroxide ion. However, the rate of hydrolysis of t-butyl chloride in aqueous ethanol is almost unaffected by addition of potassium hydroxide. Suggest a reason for this and explain why this effect is observed with a t-butyl compound. Illustrate your answer.

When the three benzaldehydes shown below were exposed to HCN under identical conditions it was found that the equilibrium constants, K, for the three cyanohydrin formation reactions were different. Based on principles that govern equilibrium processes for reversible carbonyl addition reactions, place the K values for the three reactions in ascending order (smallest to largest). Briefly justify your answer. (Hint: Recall that electron deficient carbonyls tend to react faster with nucleophiles and have larger equilibrium constants for the addition reaction.) H X O + HCN pH ~ 9-10 X = H, NO₂, OCH 3 OH H+CN X

Mention and Write the following reaction mechanisms: a) thermal dehydration of 4-t-butylcyclohexanol with phosphoric acid as catalyst; b) addition of molecular bromine to the C= C double bond of 4-t- butylcyclohexene;

Write an equation(s) to illustrate the mechanism for the dehydrohalogenation of 2-bromo-2-methylbutane. Give the major product expected from the mechanism and use arrows to indicate electron flow. Why is this reaction referred to as a concerted process?