Problem un-32

1
Problem un-32

• Hint
• There are 2 separate mono-substituted aromatic
  rings in that molecule. As they have very similar
  shifts do not try to analyze fully all the
  protons/carbons but you should be able to assign
  at least the C1 carbon on those rings and the
  ortho position.
•  
• Use first the HSQC to determine how many protons
  are coupled to each carbons. This should help you
  determining which protons are from CH and CH2
  groups. Then using COSY, try to find to which
  protons the CHs are coupled to.

2
C21H24O3
2 x ortho
2 phenyl
3
C13-NMR
C- O
4
HSQC
?
C21H24O3
- 2 x C6H5 CO2
?
?
?
?
?
?
?
C8H14O
CH2
?
CH2
?
CH2
?
CH2
?
CH
CH2 - O
CH2 - O
CH- O
5
H-NMR
CH2 - O
CH2 - O
?
CH- O
?
?
CH
?
?
?
?
?
6
COSY
7
COSY
?
?
?
CH-O
?
?
CH
?
?
?
?
?
?
?
CH2
?
CH2
?
CH2
?
CH-O
CH
CH2
?
8
summary
C21H24O3
?
?
?
?
CH2 - O
We need HMBC to put pieces together
9
HMBC
CH2 O-Ph
?
CH- O
CH
?
?
?
?
?
?
?
CH
CH2 - O
CH2 O-Ph
CH- O
ortho
CH2 -
10
Final structure