Chapter 8.11, Problem 18P

Interpretation Introduction

Interpretation:

The substitutive IUPAC name, including stereochemistry, for the structure of disparlure is to be written.

Concept introduction:

According to substitutive IUPAC nomenclature, the epoxide is considered as epoxy substituent at alkane parent chain.

The three dimensional spatial arrangement of substituents at a chirality center is called the absolute configuration.

The Cahn-Ingold-Prelog rule system ranks the substituents in the chirality center in the order of decreasing atomic number. Higher atomic number takes precedence over lower atomic number for the substituent.

When two atoms directly attached to the chirality center are the same, then compare the atoms attached to them on the basis of their atomic numbers. Precedence is determined at the first point of difference.

An atom that has multiple bonds is considered to be replicated as a substituent on that atom.

Isotopes qualify as different substituents at a chirality center depending on their atomic masses.

After the substituents at the chiral center are ranked with decreasing priority order, the next step is to orient the molecule so that the bond to the lowest ranked substituent points away from the observer. This is used to determine if the sequence of decreasing priority of the other three substituents is clockwise or counterclockwise. If this path is clockwise, then the configuration is $R$, and if it is counterclockwise, the configuration is $S$.