no notes

1
no notes
Another determine-the-structure problem
C11H15NO
4
t
6
q
2
2
1
d
d
s
1. Formula C11H15NO ? 5 degrees of unsaturation
(Ar ?)
2. 5 signals (!) in 12246 ratio ? CH 4 CH2
2 CH3
CH 2 CH-CH 2 CH2 2 CH3
CH 2 CH-CH 2 CH2CH3
3. 2H-2H doublet-doublet pattern in Ar region ? 2
equiv. CH-CH
4. 4H-6H quartet-triplet pattern ? 2 equiv.
CH2CH3
5. remaining 2 C are part of Ar ring
6. 1H singlet d ? HCO (aldehyde)
7. 4H quartet d ? N(CH2CH3)2
2
A typical determine-the-structure problem
no notes
1. Formula C4H8O2 shows 1 element of unsaturation
one ring or one double bond
2. Three signals in an integration ratio of 233
CH2 two CH3
3. Quartet-triplet pattern in 23 integration
ratio
-CH2CH3 fragment
4. Singlet worth 3 H
-CH3 fragment
5. remaining atoms CO2 cannot form a ring
1 e.u. is a CO
6. chemical shift of quartet suggests heteroatom
-OCH2CH3 fragment
CH3COOCH2CH3
3
no notes
Another determine-the-structure problem
possible answer
1. Formula C4H5O2Cl implies 2 degrees of
unsaturation.
2. Three signals in 113 integ. ratio implies 2
CH CH3
actual answer
3. J value implies cis-CHCH
4. Chemical shift of CH3 singlet implies OCH3
5. Remaining atoms -Cl and CO or ring C-O ?
IR 1736 cm-1