Show how each of the following compounds can be synthesized from an alkene:
b.

Verified step by step guidance

1. Identify the target compound: The given compound is a vicinal dibromide, meaning two bromine atoms are attached to adjacent carbon atoms in the molecule.
2. Choose an appropriate alkene precursor: To synthesize a vicinal dibromide, the starting material should be an alkene with the same carbon skeleton as the target compound. In this case, the alkene would be 2-butene.
3. Select the reaction conditions: Vicinal dibromides are typically formed by the addition of bromine (Br₂) to an alkene in an inert solvent such as carbon tetrachloride (CCl₄). This reaction proceeds via an electrophilic addition mechanism.
4. Describe the mechanism: When bromine reacts with the alkene, the π-electrons of the double bond attack the bromine molecule, forming a bromonium ion intermediate. The second bromine atom then attacks the more substituted carbon of the bromonium ion, leading to the formation of the vicinal dibromide.
5. Verify regioselectivity and stereochemistry: The addition of bromine to the alkene is anti-addition, meaning the bromine atoms will add to opposite faces of the double bond. Ensure the stereochemistry matches the target compound.

Key Concepts

Alkene Reactivity

Alkenes are unsaturated hydrocarbons characterized by at least one carbon-carbon double bond. Their reactivity is primarily due to this double bond, which can undergo various reactions such as electrophilic addition, oxidation, and polymerization. Understanding the types of reactions that alkenes can participate in is crucial for synthesizing other compounds from them.

Synthesis Pathways

Synthesis pathways refer to the step-by-step methods used to convert one compound into another. In organic chemistry, this often involves a series of reactions, including functional group transformations and rearrangements. Identifying the appropriate synthesis pathway from an alkene to the target compound requires knowledge of reaction mechanisms and the properties of intermediates formed during the process.

Functional Group Transformations

Functional group transformations involve changing one functional group in a molecule to another, which is essential in organic synthesis. For example, alkenes can be converted into alcohols, halides, or carbonyl compounds through various reactions. Recognizing how to manipulate functional groups allows chemists to design effective synthetic routes to achieve desired products from alkenes.