One of the constituents of turpentine is α-pinene, formula C₁₀H₆. The following scheme (called a “road map”) gives some reactions of α-pinene. Determine the structure of α-pinene and of the reaction products of A through E.

Cyclohexene is dissolved in a solution of lithium chloride in chloroform. To this solution is added one equivalent of bromine. The material isolated from this reaction contains primarily a mixture of trans-1,2-dibromocyclohexane and trans-1-bromo-2-chlorocyclohexane. Propose a mechanism to show how these compounds are formed.

Draw an approximate reaction-energy diagram showing the curves for the two possible pathways for ionic addition of HBr to 1-methylcyclohexene. (a) Formation of the major product, 1-bromo-1-methylcyclohexane, and (b) formation of the minor product, 1-bromo-2-methylcyclohexane. Point out how these curves show that 1-bromo-1-methylcyclohexane should be formed faster.

In contact with a platinum catalyst, an unknown alkene reacts with three equivalents of hydrogen gas to give 1-isopropyl-4-methylcyclohexane. When the unknown alkene is ozonized and reduced, the products are the following:

Deduce the structure of the unknown alkene.

The sex attractant of the housefly has the formula C₂₃H₄₆. When treated with warm potassium permanganate, this pheromone gives two products: CH₃(CH₂)₁₂COOH and CH₃(CH₂)₇COOH. Suggest a structure for this sex attractant. Explain which part of the structure is uncertain.

Unknown X, C₅H₉Br does not react with bromine or with dilute KMnO4. Upon treatment with potassium tert-butoxide, X gives only one product, Y, C₅H₈. Unlike X, Y decolorizes bromine and changes KMnO₄ from purple to brown. Catalytic hydrogenation of Y gives methylcyclobutane. Ozonolysis–reduction of Y gives dialdehyde Z, C₅H₈O₂. Propose consistent structures for X, Y, and Z. Is there any aspect of the structure of X that is still unknown?

Propose a mechanism for the following reaction.