Question

Spr 19 CHEM332 2. Draw a structure of formula CsH,N that is consistent with both the 'H and 1IC NMR spectra given below Clearly label the H's and C's on your structure with letters and assign them to the appropriate peaks on each NMR spectrum. [8 pts 5 4 3 21 Ppm 11 10 97 Peak data for 'H NMR (ppm): 2.55 (sextet, 1H), 1.63 (quintet, 2H), 1.32 (doublet 3H), 1.1 (triplet, 3H). 200 180 160 140120 100 0 40 20 ppm Peak data for叱NMR (ppm): 123, 27.4, 27.1, 17.7, 11.4.

Answer 1

Degree of unsaturation = C - H/2 +N/2 +1 = 5-9/2 +1/2 +1 = 3.

Since five signals are obtained in 13C NMR but only four in H NMR, thus all five carbons are different and one carbon don't have hydrogen. So, only possibility is presence of CN group. Also peak around 123 in 13C NMR means CN group.

Sextet for one proton means CH group is attached to CH3 and CH2 group. This CH3 give doublet. Also triplet for three protons means a CH3 group is attached next to CH2. So, combining all these information, structure become :

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