1. Match the following to their IR spectra (30 points) Look for absorption bands in decreasing order of importance: a e a 2941 1716 d f b 3333 c b 1466 1.the - absorption(s) between 3100 and 2850 cm-1. An absorption above 3000 cm-1 indicates =, either alkene or aromatic. onfirm the aromatic ring by finding peaks at 1600 and 1500 cm-1 and - out-of-plane bending to give substitution patterns below 900 cm-1. onfirm alkenes with an absorption generally at 1640-1680 cm-1. - absorption between 3000 and 2850 cm-1 is due to aliphatic hydrogens. 2. the carbonyl (=) absorption between 1690-1760cm-1; this strong band indicates either an aldehyde, ketone, carboxylic acid, ester, amide, anhydride or acyl halide. The an aldehyde may be confirmed with - absorption from 2840 to 2720 cm-1. 3.the - or - absorption between 3200 and 3600 cm-1. This indicates either an alcohol, - containing amine or amide, or carboxylic acid. For -2 a doublet will be observed. c 3026 3341 1650 1450 d 3034 1685 1617 4. the - absorption between 1080 and 1300 cm-1. These peaks are normally rounded like the - and - peak in 3. and are prominent. arboxylic acids, esters, ethers, alcohols and anhydrides all containing this peak. 5. the and triple bond absorptions at 2100-2260 cm-1 are small but exposed. e 3086 2820 2766 1703 2966 1731 f 2817 2716 7. structure of aromatic compounds may also be confirmed from the pattern of the weak overtone and combination tone bands found from 2000 to 1600 cm-1.
1. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR 8.07 ppm (d, J=7.9 z, 2) 7.32 ppm (d, J=7.9 z, 2) 2.35 ppm (s, 3) IR 3109 1596 1512 1353 para substituted 2.35 ppm: Methyl ketone or Me-aromatic
1. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR 8.07 ppm (d, J=7.9 z, 2) 7.32 ppm (d, J=7.9 z, 2) 2.35 ppm (s, 3) IR 3109 1596 1512 1353 para substituted 2.35 ppm: Methyl ketone or Me-aromatic IR: nitroarene, not a ketone
1. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR 8.07 ppm (d, J=7.9 z, 2) 7.32 ppm (d, J=7.9 z, 2) 2.35 ppm (s, 3) IR 3109 1596 1512 1353 para substituted 2.35 ppm: Methyl ketone or Me-aromatic IR: nitroarene, not a ketone
2. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR 7.22 ppm (d, J=7.9 z, 2) 7.45 ppm (d, J=7.9 z, 2) 2.41 ppm (s, 3) IR 2229 1609 1509 para substituted 2.41 ppm: Methyl ketone or Me-aromatic
2. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR 7.22 ppm (d, J=7.9 z, 2) 7.45 ppm (d, J=7.9 z, 2) 2.41 ppm (s, 3) IR 2229 1609 1509 para substituted 2.41 ppm: Methyl ketone or Me-aromatic IR: arylcyanide, not a ketone
3. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR IR 8.17 ppm (t, J=2.1 z, 1) 7.96 (dt, J=8.0, 2.1 z, 1) 7.67 (dt, J=7.7,2.1 z, 1) 7.31 (dd, J=8.0, 7.7 z, 1) 3.91 ppm (s, 3) 1571 1436 1729 meta substituted 3.91 ppm: Methyl ester 2.1 2.1 7.7 8.1 R R' 2.1
3. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR IR 8.17 ppm (t, J=2.1 z, 1) 7.96 (dt, J=8.0, 2.1 z, 1) 7.67 (dt, J=7.7,2.1 z, 1) 7.31 (dd, J=8.0, 7.7 z, 1) 3.91 ppm (s, 3) 1571 1436 1729 meta substituted 3.91 ppm: Methyl ester 2.1 7.7 8.1 2.1 R R' 2.1 IR: arylester, 1729 no nitro,, ketone from MR, we know there is not aryl-me
3. ircle the structure of the product that corresponds to the 1 MR and IR data below. ircle only one structure 2 2 2 Me Me Me 1 MR IR 8.17 ppm (t, J=2.1 z, 1) 7.96 (dt, J=8.0, 2.1 z, 1) 7.67 (dt, J=7.7,2.1 z, 1) 7.31 (dd, J=8.0, 7.7 z, 1) 3.91 ppm (s, 3) 1571 1436 1729 meta substituted 3.91 ppm: Methyl ester 2.1 7.7 8.1 2.1 R R' 2.1 IR: arylester, 1729 no nitro,, ketone from MR, we know there is not aryl-me
(24 points) (not all compounds have a match) 1. Match the following to their IR spectra a 2 b c d a b 1374 1670 1552 c d 1776 1750
5. McLafferty rearrangements of the molecules depicted below will give rise to fragments that can be detected by mass spectrometry. ircle the fragments that are observed. You may need to circle more than one answer for each! (24 points) The McLafferty Rearrangment: 120 121 122 R 70 ev R Y Y must have gamma proton R R Y 120 121 122 Y 120 121 122 120 121 122 120 121 122 120 121 122 120 121 122 120 121 122
1. Match the following to their IR spectra (24 points) (not all compounds have a match) d l c a b a 2120 b 3301 1585 1603 1689 c 2249 d 1716