Final answer:
To determine the configuration at a chiral center, assign priorities based on atomic number, orient the molecule appropriately, and use the R/S system based on the clockwise or counterclockwise arrangement of the groups. Fisher projections may also be used to represent the spatial orientation of the substituents.
Step-by-step explanation:
To identify the configuration for the indicated chiral center, one must assign priorities based on the atomic numbers of the atoms directly attached to the chiral center. The atom with the highest atomic number gets the highest priority (#1), and the one with the lowest gets the lowest priority (#4). The molecule is then oriented so that the group with the lowest priority is pointing away from you. If the sequence from the highest to the third-highest priority is clockwise, the configuration is R. If it is counterclockwise, the configuration is S. These descriptors should be placed within small brackets at the beginning of the IUPAC name, separated by a hyphen.
Fisher projections help to show the configuration of chiral centers. In Fisher projections, the chiral center is typically at the intersection of the horizontal and vertical lines, with horizontal lines representing bonds that project forward and vertical lines representing bonds that project backward. This clearly delineates the spatial arrangement of the substituents around the chiral center.
A chiral compound has two configurations that are non-superimposable mirror images of each other; these are known as enantiomers. The conversion between these forms requires a chemical change, as they are distinct compounds.