Question

You have a bottle of a compound having the formula \(\mathrm{C}_{6} \mathrm{H}_{10}\). You know it contains a terminal alkyne. What alkyne does it need to be in order to make 2,2 -dimethyl-3octyne most directly?

Short answer

The alkyne you need is 1-hexyne.

Step-by-step solution

Determine the properties of the compound

The given compound has the molecular formula \(\text{C}_{6}\text{H}_{10}\), indicating it is an alkyne because it has fewer hydrogen atoms compared to an alkane with the same number of carbons. Its structure must contain a triple bond.

Identify the terminal alkyne

A terminal alkyne has the \(\text{-C}\text{≡}\text{CH}\) group at the end of its carbon chain. This means we need to identify a structure with such a group and fit the molecular formula \(\text{C}_{6}\text{H}_{10}\).

Consider desired final product

The final product is 2,2-dimethyl-3-octyne. This product indicates that we need to add a 2,2-dimethylpropyl group to the terminal alkyne.

Determine which alkyne can form the desired product

The precursor alkyne required would have to be reacted with a reagent such as an alkyl halide. To directly form 2,2-dimethyl-3-octyne, the alkyne should be 1-hexyne \(\text{CH}_3\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-C≡CH}\).

Verification

Ensure that the terminal alkyne, 1-hexyne, can undergo the reaction to yield 2,2-dimethyl-3-octyne, fitting the molecular requirements.

Key concepts

Alkyne Reactions

Alkyne reactions are crucial in organic chemistry. Triple bonds in alkynes make them highly reactive and versatile for various transformations. Alkyne reactions often involve additions to the triple bond, leading to diverse products. Common reactions include:

• Hydrogenation: Adding hydrogen atoms to convert alkynes to alkanes or alkenes.
• Hydrohalogenation: Adding hydrogen halides to form halogenated alkenes.
• Hydration: Adding water molecules to form ketones or aldehydes.

Each of these reactions depends on the reagents and conditions used. Understanding these transformations helps in predicting the final products in organic synthesis.

Molecular Formula Analysis

Analyzing a molecular formula involves determining the number and types of atoms present in a compound. For instance, the formula \( \text{C}_{6}\text{H}_{10} \) suggests an alkyne due to the hydrogen deficit compared to an alkane (which would have \( \text{C}_6\text{H}_{14} \)). This aligns with the presence of a triple bond, as alkynes have the general formula \( \text{C}_n\text{H}_{2n-2} \).
In this task, we were given \( \text{C}_{6}\text{H}_{10} \) and asked to determine the terminal alkyne. Knowing the molecular formula helps to narrow down the possible structures. With a terminal alkyne, the \( \text{-C≡CH} \) group is crucial. Once identified, it's easier to determine how the molecule can be transformed into the desired product.

Organic Synthesis

Organic synthesis involves constructing complex molecules from simpler ones. It requires a detailed understanding of reactions and reagents to achieve the desired product. In this case, the goal is to synthesize 2,2-dimethyl-3-octyne from a compound with the formula \( \text{C}_{6}\text{H}_{10} \).
This process involves:

• Identifying the starting material: Here, it's 1-hexyne due to its terminal alkyne group.
• Choosing the right reagents: An alkyl halide like 2,2-dimethylpropyl bromide is needed to add the 2,2-dimethylpropyl group.
• Performing the reaction: This might involve using a base to deprotonate the terminal alkyne, making it reactive towards the alkyl halide.

Successful organic synthesis is about understanding each step and predicting the outcomes to achieve the intended product efficiently.