What is the correct structure for (S)-4-cyclohexyl-3-methyl-2-butanone?
A)I
B)II
C)III
D)IV

Question

What is the correct structure for (S)-4-cyclohexyl-3-methyl-2-butanone? 
A)I 
B)II 
C)III 
D)IV

Quizplus · Accepted Answer

The correct structure for (S)-4-cyclohexyl-3-methyl-2-butanone is determined by the following steps: 
1. Identify the longest carbon chain, which is 5 carbons in this case (the butanone part).
2. Number the carbons of the butanone chain starting with the carbon closest to the ketone group. This carbon is assigned number 1.
3. Determine the position of the substituents on the chain and name them using the appropriate prefixes. In this case, there is a methyl group at the 3-position and a cyclohexyl group at the 4-position.
4. Assign the stereochemistry at the chiral carbon (marked with an asterisk) based on the R/S system. 
The correct structure for (S)-4-cyclohexyl-3-methyl-2-butanone is therefore option III.

What Is the Correct Structure for (S)-4-Cyclohexyl-3-Methyl-2-Butanone