Heterocycles Part 1: Furan, Thiophene, and Pyrrole

We've mentioned heterocycles before. They are cyclic molecules where one or more atoms in the ring are not carbon. Typically these involve oxygen, nitrogen, and sulfur. But there are so many different heterocycles. Different sizes, some aromatic and some not, and many of them are important for synthesis. Let's look at a few key heterocycles now, those being furan, thiophene, and pyrrole.