Proline Catalyzed Aldol Reaction

[Qasim Ali]

What is meant by 20 vol% in reaction given Proline-Catalyzed Direct Asymmetric Aldol.pdf

plz help

Edited April 19, 2013 by Qasim Ali

[pwagen]

I couldn't find any mention of any vol %, much less 20. However, what 20 vol % means 20 % measured by volume. So if you have 0.8 l of distilled water, then add 2 dl (0.2 l) of salt, it would have a 20% volume percentage of salt.

 

http://en.wikipedia.org/wiki/Volume_percent

 

What I could find in the text was mol %, which is another way of measuring a concentration. If I'm not reading it wrong, it's the ratio of the molar mass of the salt and the average molar mass of the full solution.

 

http://en.wikipedia.org/wiki/Mole_fraction#Mole_percentage

[?synthetic?]

hi, stuck on something i did, that i cant explain. when i attempted the aldol reaction of 3-(benzyloxy)-2,2-dimethylpropanal it didnt work. my old supervisor said it was because it underwent a wagner meerwein rearrangement (one of the methyl migrated). to me from the nmr i couldnt tell how he knew because it looked like a mess. how and why would this happen. i have looked at the mechanism of this rearrangement and understand it sort of but why in this case. how could i reason it for my thesis. ps the aldols that were attempted were, evan's oxazolidinone using boron triflate, oppolzer sultam using ticl4 and then a direct crossed aldol using proline and propanal. thanks in advance. he also said this was common for this type of aldehyde (one with gem methyls)??