Counting chiral centers in artemisinin's structure

Steps:

• Examine artemisinin's formula: C15H22O5, a sesquiterpene with peroxide bridge and lactone ring.
• Identify chiral centers as tetrahedral carbons bonded to four different groups.
• Locate them at C1 (bridgehead), C5 (peroxide attachment), C6 (methyl group), C7 (peroxide), C8 (side chain), C9 (ring junction), and C12 (lactone).
• Total: seven chiral carbons confirmed by standard stereochemistry analysis.

Why C is correct:

• A chiral center requires a carbon with four distinct substituents; artemisinin has exactly seven such atoms per IUPAC definition.

Why the others are wrong:

• A: Ignores three centers in the bicyclic and peroxide regions.
• B: Misses the C12 lactone carbon.
• D: Counts the oxygen in the peroxide as chiral, which it is not.

Final answer: C