Chapter 7, Problem 39P

Give the IUPAC name for each compound, including any R, S designation.

a. b.

Interpretation Introduction

(a)

Interpretation: The IUPAC name of the given compound, including any R,S designation, is to be stated.

Concept introduction: One should follow the given four steps to give the IUPAC name of a compound. The first step is naming of longest parent chain. The second step is numbering of chain. The third step is naming and numbering of substituents. The fourth step is combining the all parts.

Answer to Problem 39P

The IUPAC name of the given compound is (R)-$2$-bromo-$5$-ethylheptane.

Explanation of Solution

The black balls of the given structure represent carbon atoms, the white balls represent hydrogen atoms and the brown ball represent bromine atom. Hence, the complete structure of the compound is,

Figure 1

The carbon atom at which bromine atom is attached is chiral in nature. The lowest priority $\left(\text{H}\right)$ group at stereogenic center lies toward the backside and the circle rotates in the clockwise direction as shown in Figure 2.

Figure 2

Hence, the configuration of stereogenic center is R.

Bromine group and ethyl group are present on the second and fifth carbon atom, respectively, of a chain of seven carbon atoms as shown in Figure 3.

Figure 3

Therefore, the IUPAC name of the given compound is (R)-$2$-bromo-$5$-ethylheptane.

Conclusion

The IUPAC name of the given compound is (R)-$2$-bromo-$5$-ethylheptane.

Interpretation Introduction

(b)

Interpretation: The IUPAC name of the given compound, including any R,S designation, is to be stated.

Concept introduction: One should follow the given four steps to give the IUPAC name of a compound. The first step is naming of longest parent chain. The second step is numbering of chain. The third step is naming and numbering of substituents. The fourth step is combining the all parts.

Answer to Problem 39P

The IUPAC name of the given compound is (1R)-$1$-chloro-$3$-isopropylcyclopentane.

Explanation of Solution

The black balls of the given structure represent carbon atoms, the white balls represent hydrogen atoms and the green ball represent chlorine atom. Hence, the complete structure of the compound is,

Figure 4

The carbon atom at which chlorine atom is attached is chiral in nature. The lowest priority $\left(\text{H}\right)$ group at stereogenic center lies toward the front side and the circle rotates in the anticlockwise direction as shown in Figure 5.

Figure 5

Hence, the configuration of stereogenic center is R.

Chlorine group and isopropyl group are present on the first and third carbon atom, respectively, of a cyclopentane ring as shown in Figure 6.

Figure 6

Therefore, the IUPAC name of the given compound is (1R)-$1$-chloro-$3$-isopropylcyclopentane.

Conclusion

The IUPAC name of the given compound is (1R)-$1$-chloro-$3$-isopropylcyclopentane.