Extraction of Carvone

Carvone Extraction Exercise
the whole TLC plate and blue or brow spots where the material ran. Be sure not to overheat the plate or
it may crack. Once done, check your TLC plate with your TA.
Draw a picture of the stained plates in your notebook and determine the Rf values. Can you find the redbrown
carvone spot on all four samples? Can you tell by the spots which enantiomer is contained in
spearmint and which is in caraways seeds?
14) Go see the IR demonstration and receive a copy of the IR for both pure carvone samples if you
haven't already. Do the two enantiomers have distinctly different peaks? Could you tell the difference
between enantiomers based on the IR spectra?
15) Smell the pure samples of + and - carvone and then smell some unused caraway and spearmint
leaves. Can you tell by smell which of the enantiomers is from spearmint and which is from caraway?
Post Lab Questions
Page 6 of 6
1. In this lab you used three methods to attempt to distinguish between enantiomers. Outside of these
three, there is a common method used for distinguishing between enantiomers or determining how
much of one enantiomer is present in excess. What is this method?
2. Which methods that you used in this lab (IR, TLC, smell) proved to be effective in distinguishing
enantiomers?
3. Separating enantiomers from a mixture is difficult but possible. Since these compounds have the
same melting point, boiling point, and density as well as other properties, there is not much that
allows a chemist to separate the enantiomers. Think of or find a method that will allow a chemist
to separate enantiomers.
4. What functional groups do you observe in the IR Spectrum?
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7/26/2010