fischer projection que.

[predentgal]

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Why is D the answer and not B??I hate these problems with a passion😡

Please help!!

http://img713.imageshack.us/img713/995/85677075d.png

 

[Erhatstil]

these problems are a bit slow going, theres not really a quicker way to do them other than assigning configurations to everything. fischer projection for choice D is 1R, 2R and so is the structure. just make sure to switch the dash and wedge for carbon 2 because we need the lowest priority (H) on the dash. It appears S, but its really R because we switched them. Remember on your fischer projections, lowest priority needs to be on vert. axis or the configuration is switched, like we did here. hope this helps.

 

[predentgal]

It did thanks!!How about this question
http://img18.imageshack.us/img18/3016/78869360.png

Don't the 2 compunds in E represent an ether and an alcohol. Wouldn't that mean that they could be distinguished in an IR?

 

[dentaldoc1515]

A is the correct answer because the difference between a OH and C=O is larger. OH is around 3400 and C=O is around 1700..just remember that.

 

[JBarr29]

A is the correct answer because the difference between a OH and C=O is larger. OH is around 3400 and C=O is around 1700..just remember that.

also the carboxy acid ir spectra produces a HUGE peak spanning pretty far. You would definitely be able to distinguish between the carbonyl and carboxy acid