Chapter C, Problem C.30P

Interpretation Introduction

(a)

Interpretation:

The IUPAC name of the given compound is to be determined.

Concept introduction:

When assigning priorities to substituents, the atom having the greater atomic number has the higher priority. In case of comparison between isotopes, the one having the greater atomic mass gets the higher priority.

When the fourth priority substituent is pointing away (it is attached by a dash bond) and the first, second, and third priority substituents are arranged clockwise, the configuration is R.

When the fourth priority substituent is pointing away (it is attached by a dash bond) and the first, second, and third priority substituents are arranged counterclockwise, the configuration is S.

If the fourth priority substituent is attached by a wedge bond, then the clockwise or counterclockwise arrangement of the first, second, and third priority substituents is determined, and that arrangement is reversed before assigning R or S.

If the fourth priority substituent is in the plane of the page, then it is switched with the substituent that points away. Then the clockwise or counterclockwise arrangement of the first, second, and third priority substituents is determined, and that arrangement is reversed before assigning R or S.

When writing the IPUAC name, the R or S designation is written in parenthesis for each asymmetric carbon atom, and hyphens are used to separate those designations from the rest of the IUPAC name.

Interpretation Introduction

(b)

Interpretation:

The IUPAC name of the given compound is to be determined.

Concept introduction:

In a Fischer projection, the vertical bonds point away from the observer while the horizontal ones point towards the observer.

If the fourth priority group attached to a chiral center is on a vertical bond, then the configuration of that chiral center is decided by the clockwise or counterclockwise direction of the groups having first, second, and third priority.

If the fourth priority group attached to a chiral center is on a horizontal bond, then the configuration of that chiral center is reversed as compared to the one shown by the clockwise or counterclockwise direction of the groups having first, second, and third priority.

When assigning priorities to substituents, the atom having the greater atomic number has the higher priority.

In case of comparison between isotopes, the one having the greater atomic mass gets the higher priority.

When writing the IPUAC name, the R or S designation is written in parenthesis for each asymmetric carbon atom, and hyphens are used to separate those designations from the rest of the IUPAC name.

Interpretation Introduction

(c)

Interpretation:

The IUPAC name of the given compound is to be determined.

Concept introduction:

When assigning priorities to substituents, the atom having the greater atomic number has the higher priority. In case of comparison between isotopes, the one having the greater atomic mass gets the higher priority.

When the fourth priority substituent is pointing away (it is attached by a dash bond) and the first, second, and third priority substituents are arranged clockwise, the configuration is R.

When the fourth priority substituent is pointing away (it is attached by a dash bond) and the first, second, and third priority substituents are arranged counterclockwise, the configuration is S.

If the fourth priority substituent is attached by a wedge bond, then the clockwise or counterclockwise arrangement of the first, second, and third priority substituents is determined, and that arrangement is reversed before assigning R or S.

If the fourth priority substituent is in the plane of the page, then it is switched with the substituent that points away. Then the clockwise or counterclockwise arrangement of the first, second, and third priority substituents is determined, and that arrangement is reversed before assigning R or S.

When writing the IPUAC name, the R or S designation is written in parenthesis for each asymmetric carbon atom, and hyphens are used to separate those designations from the rest of the IUPAC name.

Interpretation Introduction

(d)

Interpretation:

The IUPAC name of the given compound is to be determined.

Concept introduction:

In a Fischer projection, the vertical bonds point away from the observer while the horizontal ones point towards the observer.

If the fourth priority group attached to a chiral center is on a vertical bond, then the configuration of that chiral center is decided by the clockwise or counterclockwise direction of the groups having first, second, and third priority.

If the fourth priority group attached to a chiral center is on a horizontal bond, then the configuration of that chiral center is reversed as compared to the one shown by the clockwise or counterclockwise direction of the groups having first, second, and third priority.

When assigning priorities to substituents, the atom having the greater atomic number has the higher priority.

In case of comparison between isotopes, the one having the greater atomic mass gets the higher priority.

When writing the IPUAC name, the R or S designation is written in parenthesis for each asymmetric carbon atom, and hyphens are used to separate those designations from the rest of the IUPAC name.