Explain why in the Ritter reaction with hydrogen cyanide and t-butyl alcohol, the product is t-butylamine and not t-buty1 cyanide (or trimethylacetic acid).

The Ritter reaction is a nucleophilic addition reaction that involves the formation of a carbocation from a tertiary alcohol, followed by the addition of a nitrile to generate a secondary amine. The overall mechanism can be described as follows: 1. The tertiary alcohol reacts with a strong acid, such as H2SO4, to form a carbocation. 2. The carbocation reacts with the nitrile to form a new carbon-nitrogen bond, generating an N-alkylated nitrile intermediate. 3. The intermediate undergoes hydrolysis (treatment with water) to yield a secondary amine and an alkylated carboxylic acid. In our case, the reaction between hydrogen cyanide and t-butyl alcohol will follow this mechanism.

The first step of the reaction involves the generation of a carbocation from t-butyl alcohol. This is achieved through protonation of the alcohol by a strong acid, typically H2SO4 or HCl. The protonated alcohol then loses a water molecule to form a carbocation: \[t-BuOH + H^+ \rightarrow t-BuOH_2^+ \] \[t-BuOH_2^+ \rightarrow t-Bu^+ + H_2O \]

Next, the carbocation reacts with hydrogen cyanide, which acts as a nucleophile due to the presence of a highly polarized carbon-nitrogen triple bond. The nucleophilic attack occurs at the carbon of the carbocation, forming a new carbon-nitrogen bond in the process: \[t-Bu^+ + HCN \rightarrow t-BuCNH_2^+ \]

Finally, the N-alkylated nitrile intermediate undergoes hydrolysis. This step takes place under aqueous conditions, where the nitrile group is attacked by a water molecule, resulting in the formation of a secondary amine (t-butylamine) and a carboxylic acid (acetic acid): \[t-BuCNH_2^+ + H_2O \rightarrow t-BuNH_2 + CH_3COOH \]

The Ritter reaction forms t-butylamine and acetic acid instead of other products because of the carbocation intermediate formed from t-butyl alcohol and the nucleophilic addition of hydrogen cyanide. T-butyl cyanide or trimethylacetic acid would not form under these conditions, as the reaction specifically directs the formation of a secondary amine due to the nucleophilic attack and hydrolysis steps in the mechanism. In conclusion, the formation of t-butylamine in the Ritter reaction between hydrogen cyanide and t-butyl alcohol is due to the nucleophilic addition of hydrogen cyanide to the carbocation intermediate and the subsequent hydrolysis of the N-alkylated nitrile intermediate. This process does not favor the formation of t-butyl cyanide or trimethylacetic acid, resulting in t-butylamine as the main product.