What is the configuration of the following compounds? (Use the given structures to answer the question.)

a. (-)-glyceric acid

b.(+)-isoserine

c. (+)-lactic acid

Cahn, Ingold, and Prelog devised a mechanism that, no matter which way we look at the molecule, always yields the same name (unlike the wedge and dash notation).

As a result, this system is also known as the absolute Configuration or, more popularly, the R and S system.

• Because the group with thelowest priority is on the hatched wedge.
• The arrow drawn from the COOH group to thegroup isclockwise.
• (-)-glyceric acid has the R configuration.

• Because the group with the lowest priority is on the hatched wedge.
• The arrow drawn from the COOH group to the group is clockwise.
• (+)-isoserinehas the R configuration.

• Because the group with the lowest priority is on the hatched wedge.
• The arrow drawn from the COOH group to the group isclockwise.
• (+)-lactic acidhas theR configuration.