So you're trying to get terpenes from anise oil, or are you trying to get anethole without terpenes in it?
When you did distillation, did you have a column with enough plates for the temperature difference between the expected constituents, and if that
meant more than a 4 or 5 plates, did you use some sort of partial take-off or at least a small condenser below the distillation head so the reflux
ratio was something like the number of plates used?
Were you distilling in vacuum? Anethole oxidizes pretty easy at elevated temperatures.
have you tried adding a small amount of solvent to the anise oil and freezing to see if the solids deposited are different than what's left in
solution? I know adding and equal amount of ethanol to calamus oil and freezing tends to deposit asarones while the other materials are left in
solution.
That was not a clean separation, but repeated a few times it left a product which gave an almost theoretical yield of the pseudonitrosite. The asarone
did not have the proper melting point, but I didn't try to free it of traces of ethanol.
I suppose I should have done so with freezing/thawing/refreezing under high vacuum, but characterizing it by the pseudonitrosite was good enough for
me.
Pet ether is probably better for this purpose than ethanol as it ought to dissolve terpenes better than anethole, but ethanol worked fairly well .
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