ABSTRACT
Nineteenth-century French chemist and microbiologist Louis Pasteur was a legendary character during his lifetime and remains a scientific icon. Pasteurization of beverages and food, the germ theory of disease, a vaccine against rabies-how much can one person contribute? Well . . . before any of these achievements, Pasteur-in 1848, at the tender age of 25-laid the foundations for a new field of chemistry known as stereochemistry.1 This is the study of molecules that are stereoisomers of one another-they have the same chemical composition and the atoms of the molecules have the same connections to one another but the atoms differ in their position in three-dimensional space. Pasteur was able to prove that organic molecules having identical chemical content and connectivity can exist in uniquely different forms. Pasteur referred to his findings as molecular asymmetry. Stereochemistry has huge practical implications for the manufacture of safe drugs, and, as we will see, it is inseparably linked with life.
