Question

multiple choice 2 points
name the alkene shown. be sure to include the appropriate e or z label
brh₂ch₂c ch₂ch₂ch₃
c = c
h cl
(e)-1-bromo-4-chlorohept-3-ene
(z)-7-bromo-4-chlorohept-4-ene
(e)-7-bromo-4-chlorohept-4-ene
(z)-1-bromo-4-chlorohept-3-ene
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Explanation:

Step1: Determine the longest carbon chain

The longest carbon chain has 7 carbons (hept -).

Step2: Locate the double bond

The double bond is between carbon 3 and 4 (hept - 3 - ene).

Step3: Assign priorities

For the left - hand carbon of the double bond: \(BrCH_{2}CH_{2}-\) (higher priority) and \(H-\) (lower priority). For the right - hand carbon of the double bond: \(CH_{2}CH_{2}CH_{3}-\) (higher priority) and \(Cl-\) (lower priority). Since the higher - priority groups are on opposite sides of the double bond, it is \(E\).

Step4: Name substituents

There is a bromo group at carbon 1 and a chloro group at carbon 4. So the name is (E)-1 - bromo - 4 - chlorohept - 3 - ene.

Answer:

(E)-1-bromo-4-chlorohept-3-ene