Chemistry 130
Worksheet 3b Notes
Oregon State University
Dr. Richard Nafshun
Label all functional groups you can find (methyl groups, alcohols, ketones, etc.). How many cyclic
alkenes are fused together in these molecules? How many cyclohexanes and cyclopentanes are in each
molecule? Write the chemical formula for each molecule. Describe in which ways these molecules are
different.
Figure 1. Structure of Cortisone:
methyl groups
ketone
primary alcohol
tertiary alcohol
cyclopentane
cyclohexane
cyclohexene
Chemical formula: C21H28O5. Remember, every corner or end represents a carbon atom and each needs
to have 4 bonds. Some of the carbons in the cyclic structures have 0 or 1 hydrogen atoms.
Figure 2. Structure of Cholesterol:
methyl groups
2-methylheptane sidechain
secondary
alcohol
cyclopentane
cyclohexane
cyclohexene
Chemical Formula: C27H46O
Cholesterol does not have ketone groups, and has a heptane chain at the cyclopentane ring. It also only
has 1 alcohol group. As you probably noticed, the molecules are quite similar in shape (the ring
structures), but the body responds to them quite differently due to the arrangement of functional groups!