Chapter 9 covered a synthesis of alkynes by a double dehydrohalogenation of dihalides. A...

Chapter 9 covered a synthesis of alkynes by a double dehydrohalogenation of dihalides. A student tried to convert trans-2,5-dimethylhex-3-ene to 2,5-dimethylhex-3-yne by adding bromine across the double bond, then doing a double elimination. The infrared and mass spectra of the major product are shown here.

(a) Do the spectra confirm the right product? If not, what is it?

(b) Explain the important peaks in the IR spectrum.