If I wanted to isolate cis-3-hexanol (cis-3-hexen-1-ol; IUPAC name: (Z)-Hex-3-en-1-ol ) from grass I could start the extraction by dissolving the grass in a solution of ethanol. EtOH is a common solvent for extractions, and dissolving grass in it would leave some remaining solid, as well as a crude solution containing the cis-3-hexanol. Cis-3-hexanol is a liquid at room temperature and is soluble in ethanol but not (only to a small degree) soluble in water.

After filtering out the remaining undissolved solids, I think the next best step would be to boil off the remaining ethanol and water with both of their boils points being lower than cis-3-hexanol's boiling point at around 156.5 degrees C. This would presumably leave a crude solution containing cis-3-hexanol and other organic components extracted from the grass.

What would be the best method to further purify the remaining solution for a higher purity? Please correct me if my thought process is wrong.

Cis-3-hexanol is used in perfumes and the demand for it has increased in industry.

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    $\begingroup$ Hexenol and hexanol are not the same thing $\endgroup$ Jul 14, 2016 at 22:36

1 Answer 1


First, how much compound do you want to make?
Second, how much cis-3-hexanol is there in grass? It is probably around 0.01%, so be ready to process a lot of grass.
Third, it might be reactive (that is it can decompose).

Your best bet is to:
(1) Figure out theoretical yield (2) Do steam distillation rather than extraction (bp is 156.5 °C - good for distillation).
(3) Extract collected fraction (mostly water+ some organics including hexenol) with some light organic solvent (hexane, ether). You can try ethyl acetate (aka MEK substitute, bp = 77C), but that is the highest bp you want to go for.
(4) Split organic solution in several fractions and try washing it with water solutions of 5% baking soda and then brine (saturated solution of NaCl). Hexenol should stay in organic solvent unless it decomposes.
(5) Concentrate it under reduced pressure. If you don't have access to rotavap - let it sit in open air. You can direct fan at it if you will, but you might catch fire if you are not accurate.

You will get a drop of something that is a mix of 20 compounds. How you need to do column chromatography, which is pain even with equipment.

It doesn't sound like you have access to chemistry lab. In this case for practice purposes try extracting eugenol from cloves first. Grind cloves, place in distillation apparatus, add water, distill. Oil on top is eugenol.

Steam distillation: Shred grass, add to a gallon of water and distill it off using a lab distillary apparatus.


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