How can the following compounds be prepared using ethyne as the starting material?
a.

Verified step by step guidance

1. Identify the target compound structure from the image and determine the functional groups present. This will help in planning the synthetic route from ethyne.
2. Recognize that ethyne (C₂H₂) is a simple alkyne with a triple bond, which can undergo various reactions such as addition, substitution, and oxidation to form different functional groups.
3. Consider the addition of hydrogen (hydrogenation) to ethyne to form ethene (C₂H₄) or ethane (C₂H₆), depending on the degree of hydrogenation. This step is crucial if the target compound contains single or double bonds.
4. If the target compound contains a halogen, consider halogenation reactions. Ethyne can react with halogens like Br₂ or Cl₂ to form dihaloalkenes or tetrahaloalkanes, depending on the reaction conditions.
5. For the introduction of functional groups such as alcohols, aldehydes, or ketones, consider hydroboration-oxidation or hydration reactions. Ethyne can be converted to an aldehyde or ketone through hydroboration followed by oxidation, or to an alcohol through hydration.

Key Concepts

Ethyne as a Building Block

Ethyne, also known as acetylene, is a simple alkyne that serves as a versatile building block in organic synthesis. Its triple bond allows for various reactions, including addition reactions with electrophiles, which can lead to the formation of more complex molecules. Understanding how to manipulate ethyne's reactivity is crucial for synthesizing target compounds.

Reactions of Alkynes

Alkynes undergo a variety of chemical reactions, including hydrogenation, halogenation, and hydroboration. These reactions can modify the triple bond to form double bonds or single bonds, allowing for the construction of different functional groups. Familiarity with these reaction mechanisms is essential for predicting the products when starting from ethyne.

Functional Group Transformations

Functional group transformations involve converting one functional group into another, which is a key strategy in organic synthesis. By understanding how to perform these transformations, such as converting alkynes to alcohols or ketones, chemists can design pathways to synthesize desired compounds from ethyne. This concept is fundamental for planning synthetic routes in organic chemistry.