Counting Carbons and Chiral Centers in Steroid Structure

Steps:

• Determine the molecular formula: hydrocortisone (C21H30O5) plus acetate group (C2H2O) yields C23H32O6.
• Count carbon atoms: 17 in rings, 4 in side chain, 2 from acetate, totaling 23.
• Locate chiral centers: asymmetric carbons at positions 8, 9, 10, 13, 14, 17, 20, and 21 in the structure.
• Verify total: 23 carbons and 8 chiral atoms match the formula.

Why C is correct:

• Matches the standard formula C23H32O6 with 8 tetrahedral stereocenters as per steroid nomenclature.

Why the others are wrong:

• A: Carbon count is low (22 instead of 23 from missing acetate carbon).
• B: Chiral count is low (7 instead of 8, omitting one side-chain center).
• D: Assumes extra carbon (24 instead of 23, overcounting acetate).

Final answer: C