Question

Draw a structural formula for the alkene with the molecular formula \(\mathrm{C}_{5} \mathrm{H}_{10}\) that reacts with \(\mathrm{Br}_{2}\) to give each product. (a) CC(Br)C(C)(C)Br (b) CCC(C)(Br)CBr (c) CCCC(Br)CBr

Short answer

Question: Determine the structural formula of the alkene with the molecular formula \(\mathrm{C}_{5}\mathrm{H}_{10}\) that reacts with \(\mathrm{Br}_{2}\) to form each of the following products: (a) Product with SMILES notation CC(Br)C(C)(C)Br (b) Product with SMILES notation CCC(C)(Br)CBr (c) Product with SMILES notation CCCC(Br)CBr Answer: (a) The alkene that reacts with \(\mathrm{Br}_{2}\) to form the product with SMILES notation CC(Br)C(C)(C)Br is 2-methylbut-2-ene. (b) The alkene that reacts with \(\mathrm{Br}_{2}\) to form the product with SMILES notation CCC(C)(Br)CBr is 3-methylbut-1-ene. (c) The alkene that reacts with \(\mathrm{Br}_{2}\) to form the product with SMILES notation CCCC(Br)CBr is pent-1-ene.

Step-by-step solution

Product (a): Structural Formula

For product (a) with the SMILES notation CC(Br)C(C)(C)Br, the structure of the molecule is: ``` Br Br | | H3C - C - C - C - CH3 | CH3 ``` The reaction is an addition of bromine across the alkene double bond in C5H10. We need to find out the alkene from which this dibromide was formed. Remove the two bromine atoms and form a double bond between the carbon atoms where bromines were attached: ``` H3C - C = C - C - CH3 | CH3 ``` The alkene structure corresponding to product (a) is 2-methylbut-2-ene.

Product (b): Structural Formula

For product (b) with the SMILES notation CCC(C)(Br)CBr: The structure of the molecule is: ``` Br | H3C - CH2 - C - CH2 - CH3 | CH3 ``` Again, remove the two bromine atoms and form a double bond between the carbon atoms where bromines were attached: ``` H3C - CH2 - C = CH - CH3 | CH3 ``` The alkene structure corresponding to product (b) is 3-methylbut-1-ene.

Product (c): Structural Formula

For product (c) with the SMILES notation CCCC(Br)CBr, The structure of the molecule is: ``` H3C - CH2 - CH2 - CH2 - C - CH3 | | Br Br ``` Now, remove the two bromine atoms and form a double bond between the carbon atoms where bromines were attached: ``` H3C - CH2 - CH2 - CH2 - C = CH3 ``` The alkene structure corresponding to product (c) is pent-1-ene. By analyzing each product and the corresponding reactant structures, we have determined the structural formula of alkenes that reacted with \(\mathrm{Br}_{2}\) to form each product: Alkene for product (a): 2-methylbut-2-ene Alkene for product (b): 3-methylbut-1-ene Alkene for product (c): pent-1-ene