Questions:
Could you predict the sign of the rotation for the benzamide derivative of (-)-s-butylamine? Explain your answer as you did
How would you separate (+) or (-) tartaric acid from meso-tartaric acid? How would you separate (+) and (-)-tartaric acid
Q3) What would happen if you attempt to crystalline the salt formed by mixing (+)-s-butylamine and (+)-tartaric
Answers:
The sign is negative
The negative sign of given compound indicates the compound is levo rotatory by using specific rotation.
A common way of separation of tartaric acid from meso-tartaric is by use of the conversion into diastereomers, that are not mirror images of each other, where the (S-(-) and R-(+)) are separated using (L)- (+) – tartaric acid as resolving agent, the two salts formed possess different cation ions and therefore they will not be enantiomers of each other anymore, the (S)-(1)-phenylethyl ammonium-(R,R)-tartrate salt crystallizes faster than the (R)-(1)-phenylethyl ammonium-(R,R)-tartrate salt.
When the salt formed by mixing ( and tartaric acid is crystalled , diastereomers are obtained
Boiling chip will be used to ensure the molecules are active for the reaction of the (+_)-2-PSA and L-proline completely react
Filtration is done to separate the solution from the solids formed
Acetone is used in order to enable all the (+_)-2-PSA and L-proline completely react
Ice cold 6 M HCl is added to recover the resolved (+)-2-PSA
specific rotation = 9.60
Optical purity = *100 = 96%
Calculate the percentage yield on the amount of acid recovered by the whole class
Recovered acid = 3 – 0.3 = 2.7 g
