How many unsaturations are present in the following compound?
We’re being asked to determine the degrees of unsaturation for the given structure:
Recall that the degrees of unsaturation or index of hydrogen deficiency (IHD) tell us how many hydrogens are missing in a structure.
In a given structure, the IHD is:
• Rings: +1
• Double bonds: +1
• Triple bonds: +2
For a given structure, we simply need to determine the number of rings, double and triple bonds to determine the IHD.