What is the IUPAC name for the molecule shown below?

Question

Quizplus · Accepted Answer

The highest priority functional group is the alkyne, so the parent chain is hept-2-en-5-yne. The stereochemistry at the double bond is indicated by the E/Z designation, and since the substituents on carbons 4 and 5 are both on the same side of the double bond (cis), we have to choose the Z isomer. Finally, the substituent on carbon 4 is a chloro group, which is named as a substituent according to alphabetical order, and since it is on the same side as the lowest priority group (hydrogen), we use the R configuration at that carbon. Therefore, the correct IUPAC name is (2E,4R)-4-chlorohept-2-en-5-yne.

What Is the IUPAC Name for the Molecule Shown Below