Predict the products of the following reactions.
(a) sec-butyl isopropyl ether + concd. HBr, heat
(b) 2-ethoxy-2-methylpentane + concd. HBr, heat
(c) di-n-butyl ether + hot concd. NaOH

Ether cleavage is a reaction where ethers are broken down into their constituent alcohols and alkyl halides, typically in the presence of strong acids like HBr. The mechanism often involves protonation of the ether oxygen, making it a better leaving group, followed by nucleophilic attack by the halide ion. This process is crucial for predicting the products of reactions involving ethers.

Rearrangement reactions occur when a molecule undergoes a structural change to form a more stable product. In the context of ether cleavage, the formation of more stable carbocations can lead to unexpected products. Understanding how carbocation stability influences product formation is essential for predicting the outcomes of reactions involving branched ethers.

Nucleophilic substitution is a fundamental reaction mechanism in organic chemistry where a nucleophile replaces a leaving group in a molecule. In the case of ether cleavage with strong acids, the nucleophile (often a halide ion) attacks the carbon atom bonded to the leaving group, leading to the formation of new products. Recognizing the type of nucleophilic substitution (SN1 or SN2) is vital for predicting the reaction pathway and products.