Starting from 1-hexene, what is the product of the following reactions?
1. Br2, CCl4 2. xs NaNH2, then H2O 3. NaH 4. BrCH2CH2CH3
Select answer from the options below
4-nonyne
1-hexyne
2-heptyne
2-bromo-2-hexane
3-nonyne
The product of the reaction depends on the specific reaction conditions and the order in which the reactions are performed. However, based on the given reactants and reagents, the likely products are:
1. Br2, CCl4: This reaction is a halogenation reaction where the double bond of 1-hexene is broken and replaced with a bromine atom on each carbon. The product would be 1,2-dibromo-1-hexane.
2. xs NaNH2, then H2O: In this reaction, NaNH2 acts as a strong base that can deprotonate 1-hexene, resulting in the formation of a carbon-carbon triple bond. The product would be 1-hexyne.
3. NaH: NaH is a strong base that can deprotonate 1-hexyne, resulting in the formation of a carbon-carbon triple bond. Since 1-hexyne already contains a triple bond, the reaction will likely not have a significant effect on the product.
4. BrCH2CH2CH3: This reagent, bromoethane, can react with 1-hexene through a nucleophilic substitution reaction. The bromine atom will replace the hydrogen atom on the carbon adjacent to the double bond. The product would be 2-bromo-2-hexene.
Therefore, the likely product of these reactions would be 2-bromo-2-hexene.
To determine the product of each reaction, we need to understand the reaction conditions and the type of reaction taking place. Let's analyze each reaction step by step:
1. Br2, CCl4:
This reaction involves bromination, where Br2 adds across the double bond of the 1-hexene following an anti-addition mechanism. The product will have Br atoms added to the carbons that were part of the double bond. So, the product will be a compound with a bromine atom attached to the end of the hydrocarbon chain. The answer options that fit this description are 4-nonyne and 3-nonyne.
2. Excess (xs) NaNH2, then H2O:
In this reaction, NaNH2 behaves as a strong base, leading to the formation of a new carbon-carbon triple bond. This process is known as deprotonation, where a hydrogen atom from the terminal carbon of the alkyne is removed. The resulting product will, therefore, be an alkyne with one less hydrogen atom than the starting material. Since the starting material is 1-hexene, which is an alkene, the resulting product will be an alkyne containing six carbons. The correct answer option is 1-hexyne.
3. NaH:
NaH is a strong base that typically reacts with acidic hydrogens. However, in the absence of any other reactants, NaH would not cause any reaction or modification to the compound. Therefore, this step does not result in any changes, and the previously formed product, 1-hexyne, remains unchanged.
4. BrCH2CH2CH3:
This reaction involves the addition of a bromine atom to the compound 1-hexyne. Since the bromine atom adds across the triple bond of the alkyne, the product will contain a bromine atom attached to one of the carbon atoms in the triple bond. The answer option that matches this description is 2-bromo-2-hexene.
In conclusion, the product of the above reactions is 2-bromo-2-hexene.
To determine the product of the given reactions, we need to go through each step.
1. Br2, CCl4:
Br2 is a halogenation reaction that replaces a hydrogen atom with a bromine atom. In this case, 1-hexene reacts with Br2 in the presence of CCl4 (carbon tetrachloride) as a solvent. The product is 2-bromo-1-hexene.
2. xs NaNH2, then H2O:
xs (excess) NaNH2 (sodium amide) is a strong base that can deprotonate a terminal alkyne. In this reaction, the previous product, 2-bromo-1-hexene, reacts with xs NaNH2, followed by H2O. The result is the formation of an alkyne. Since we started with 1-hexene, which is an alkene, the product is 1-hexyne.
3. NaH:
NaH (sodium hydride) is another strong base that can deprotonate an alkyne. Since we already have an alkyne (1-hexyne), reacting it with NaH does not produce any new functional groups. Therefore, the product remains as 1-hexyne.
4. BrCH2CH2CH3:
Finally, 1-hexyne reacts with BrCH2CH2CH3 (2-bromoethyl ethyl ether). This reaction is an alkylation reaction that adds the 2-bromoethyl group to the alkyne. The resulting product is 2-bromo-2-hexyne.
So, the correct answer is 2-bromo-2-hexyne.