Question

Chemical Formula C6H12O 403 4,0i Opt 3.38 3.37 เก้ เท่ เก๋ เท่ เก้ เท่ เท่ เก่ เก่ ค 1.00 0.98 0.97 - --- -- 5.6 1 (ยาก) 6.0 5.8 5.6 5.4 5.1 5.0 4.8 4.6 4.4 4.2 4.0 3.8 3.6 34 3.2 3.0 2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6

The above is just one question. please answer the following according to the above.

1. Assign signals of 13C and 1H spectra as well as find the structural unit and functional group.

2. Give the structure

sample answer - as follows

1H NMR: p-substituted Ar at 7.27-7.97 ppm, benzylic CH3 group at 2.42 ppm, COOH proton at 12.9 ppm

13C NMR: carbonyl C at 167.8 ppm (ester or acid), benzylic CH3 at 21.40 ppm, 4 remaining signals are Ar carbons, two of which are quaternary, typical of a p-substituted ring

--> and finaly give a structure for the question.

Answer 1

Answer: Molecular formula = C6H120 Double bond equivalent = (C+1) - (H/2) = 7-(12/2) = (14-12)/2 = 1 The molecule contains 1 double bond

From the H'NMR data, the structure of the molecule is H'NMR data(ppm) 0.98(3H, t) 1.60(2H, 9) 3.38(2H, 3) IH 4.02(2H,d) For-CH3 group bonded with a - CH2 group For-CH2 group bonded with-CH2 and a CH3 group For-CH2 group bonded with -CH2 group and oxygen atom for -CH2 group bonded with -CH group and with oxygen atom Here, two peaks marge together and appears like multiplates. The two protons are not in the same environment. 5a appears in lower filed than 5b For-CH group bonded with two different -CH2 group 5.14(2H,m) 5.85(1H,m)

13 C-NMR data 10.62(9) For-CH3 22.93(t) For-CH2 70.02(t) 73.55(t) For-CH2 bonded with oxygen atom For-CH2 bonded with oxygen and a double bond For=CH2 116.92(t) 133.78(d) For=CH