Solution: The chemical shifts in the 13C NMR spectrum for this compound are δ 15.8, 40.1, 51.8, and 170.2. Which is the correct set of chemical shifts for the carbon atoms?

Problem

The chemical shifts in the 13C NMR spectrum for this compound are δ 15.8, 40.1, 51.8, and 170.2. Which is the correct set of chemical shifts for the carbon atoms?