There are over 100 elements in the periodic table. Many molecules contain well over 100 atoms—palytoxin (a naturally occurring compound with potential anticancer activity), for example, contains 129 carbon atoms, 221 hydrogen atoms, 54 oxygen atoms, and 3 nitrogen atoms. It’s easy to see how chemical structures can display enormous variety, providing enough molecules to build even the most complicated living creatures.

But how can we understand what seems like a recipe for confusion? Faced with the col lection of atoms we call a molecule; how can we make sense of what we see? This chapter will teach you how to interpret organic structures. It will also teach you how to draw organic molecules in a way that conveys all the necessary information and none of the superfluous.