Practice Problem 3

The discovery of penicillin in 1928 marked the beginning of what has been called the "golden age of chemotherapy," in which previously life-threatening bacterial infections were transformed into little more than a source of discomfort. For those who are allergic to penicillin, a variety of antibiotics, including tetracycline, are available. Identify the numerous functional groups in the tetracycline molecule.

Solution

This compound contains an aromatic ring fused to three six-membered cycloalkane rings. It is also an alcohol (with five OH groups), a ketone (with C=O groups at the bottom of the second and fourth rings), an amine (the N(CH₃)₂ substituent at the top of the fourth ring), and an amide (the CONH₂ group at the bottom right-hand corner of the fourth ring.)