Which of the following is the correct IUPAC name for the following structure?
S)-3-ethyl-2-methylhexane
R)-3-ethyl-2-methylhexane
S)-3-ethyl-2-methylpentane
R)-3-ethyl-2-methylpentane

Question

Which of the following is the correct IUPAC name for the following structure? 
S)-3-ethyl-2-methylhexane 
R)-3-ethyl-2-methylhexane 
S)-3-ethyl-2-methylpentane 
R)-3-ethyl-2-methylpentane

Quizplus · Accepted Answer

The longest carbon chain in this compound is six carbons long and has a methyl group on the second carbon and an ethyl group on the third carbon. The molecule can be oriented with the highest priority group, the ethyl group, either pointing up or down. When the ethyl group is pointing down, the lowest priority group, a hydrogen atom, is also pointing down. This gives a clockwise sequence of priority groups and corresponds to the (R) configuration. Therefore, the correct IUPAC name is (R)-3-ethyl-2-methylhexane.

Which of the Following Is the Correct IUPAC Name for the Following