[helper]

hello,
I tried to solve this problem and I dont know if it is good.

[discodermolide]

The signals in the aromatic portion of the spectrum indicate a different substitution pattern of the ring.
See if you can figure it out.

[helper]

yes I corect it to para - I made a mistake in drawing.
but- is it true that the N and O are conented togheter?
 or should it be a different mulecule/


**
the second picture is a correction- don't pay attention to the first.

thank you ahead.

[discodermolide]

That's OK. I have no problem with N and O being connected, Look up Weinreb Amides.

[DrCMS]

I think you need to reconsider the structure.  I agree with the para substitution of the ring but why do you think the nitrogen and oxygen are joined together?  Also on your 2nd structure you have only 2 bonds to the nitrogen.

The evidence is:
- para substituted aromatic ring - 2 peaks at ~7ppm with integration of 2H each

- CH₃ group next to 2H - triplet ~1ppm with integration of 3H
- CH₂ next to 3H - quartet ~4ppm with integration of 2H
this is most likely CH₂CH₃

- CH₃ group not coupled to any other H - single peak ~2ppm with integration of 3H

- X-H not coupled to any other H - single peak ~9ppm with integration of 1H 
X is N or O given the shift

Can you put this info together to give another structure that a chemspider search will show matches up exactly with the attached spectra including the peaks marked as impurities/TMS

[orgopete]

yes I corect it to para - I made a mistake in drawing.
but- is it true that the N and O are conented togheter?
 or should it be a different mulecule/


**
the second picture is a correction- don't pay attention to the first.

thank you ahead.

This structure only has nine carbons.

Hint, the N and O are not connected. (There are only a few ways the remaining atoms can be connected once the para substituted benzene ring is taken into account.)

[helper]

thank you all. my new answer is attached.