1600 1400 800 600 12-24 2000 1800 1200 1000 wavenumber(cm) 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 and then doing a double elimination. The infrared and mass spectra of the major product are shown here. Br hy Bez KOH heat Xcach Br (a) Do the spectra confirm the right product? If not, what is it? (b) Explain the important peaks in the IR spectrum. 100 67 95 80 60 M 10 abundance 40 20 0 10 20 30 40 50 60 70 80 90 muz 100 110 120 130 140 150 160 25 100 3 4.5 wavelength (um) 5 55 6 u 9.10 11 12 13 14 15 16 80 60 40 RE-EX 20 0 4000 3500 3000 2500 2) 2000 1800 1600 wavenumber(cm) 1400 1200 1000 800 600