Author Question: Citral, a compound found in lemons and limes, is a mixture of two isomeric alkenes, cis- and ... (Read 67 times)

ENagel · **on:** Aug 23, 2018

Citral, a compound found in lemons and limes, is a mixture of two isomeric alkenes, cis- and trans-3,7-dimethyl-2,6-octadienal. Would you expect to see two spots, one for each isomeric alkene, when you analyzed this sample by thin layer chromatography? Explain.

Question 2

One of the known compounds you analyzed, 3,7-dimethyl-1,6-octadien-3-ol, is only available as a racemic mixture. Why did you not see two spots, one for each enantiomer, when you analyzed this sample?

FergA · **Reply #1 on:** Aug 23, 2018

Answer to Question 1

The two isomers of citral are diastereomers and therefore can potentially be separated because diastereomers can have different physical properties.

Answer to Question 2

Enantiomers are identical in all respects except for how they rotate plane-polarized light and how they interact with another chiral molecule. Therefore, because neither the stationary or mobile phase is chiral, there is no means of separating the two enantiomers and they show up as a single spot.