I don't like to use solvents that have been identified as a carcinogen, mutagen, or teratogen, even at trace amounts. That is why I don't use Acetone and prefer to stick to simple alkanes or simple alkane alcohols if given a choice.
Precisely.
I just want people to understand slightly the reactivity of acetone for a second as well, so bear with me quickly here:
This is an image of acetone
You'll notice a few things:
1. It is a symmetrical molecule.
2. Each side of the ketone (C==O) bears a methyl group (CH3)
3. The central carbon makes a double bond (or a pi bond) with oxygen,
I want you to understand the following:
This molecule is not to scale, and there is much that the eye doesn't see which this molecule does in reality.
The CH3 groups are actually HUGE groups. So big that they will actually bump each other from either side of the molecule. They are also spinning around like helicopter blades at all times. Both of these effects together put strain on the "bent" bond which is centralized on the carbonyl carbon (C==O). This increases thermodynamic favorability of a reaction which will relieve that strain.
It's also worth mentioning three things about the carbonyl itself:
1. The central carbon is neither fully reduced nor fully oxidized and this increases its reactivity in either direction (its in the dead center of oxidation states so it can go either way really).
2. The oxygen draws electron density away from the central carbon, and through induction also pulls from each CH3 group--this further weakens the bond.
3. The pull of electron density also polarizes the carbonyl--such that the carbon has a delta positive charge and the oxygen has a delta negative charge. This GREATLY increases reactivity of this molecule when combined with the incomplete oxidation/reduction of the central carbon.
If you wanted to design a more reactive molecule, you'd have a hard time doing it without actually producing a carbanion or carbocation--which is extremely difficult and they are so reactive that they blink out of existence almost as soon as they are created.
The most common reaction we expect from acetone is an addition to the central carbon from an angle of attack opposite the carbonyl oxygen.
Like this reaction:
This scheme is written somewhat poorly but allow me to walk you through it.
The central oxygen molecule of water (negative charge) attacks the central carbon of acetone (positive charge). This breaks the double bond of the ketone.
When the central oxygen atom of water has made 3 complete bonds (oxygen only likes to make 2) it carries a positive charge. Oxygen is EXTREMELY electronegative and does not want to hold this positive charge, it relieves the chemical potential by losing a proton (hydrogen) which is also positively charged.
In a similar but reverse situation, when the ketone oxygen loses its second bond it goes from a partial negative charge to a complete negative charge (because it likes to make 2 bonds and it only has 1 now).
This oxygen will abstract a proton from solution (and often it will just immediately grab the one the water molecule lost)--which ends you up with two alcohol groups (OH) jutting off the central carbon as well as the two original methyl groups.
Let's look at this new molecule.
It's central carbon is unstrained--the bond angles around it are all equally spaced (109.5 degrees, in a tetrahedral configuration) give or take a few fractions of an angstrom. So the steric strain has been alleviated.
Let's look at the central carbon atom--now it has been further oxidized, and so some of the strain which pulls from the central oxidation state has also been relieved.
This fits in with what we expect. Reactions are *mostly* dependent on thermodynamic availability. This means that things naturally follow a trend of more reactive molecules ---------------> less reactive molecules.
Saying something is more reactive is the same as saying that it is less stable, under thermodynamic conditions (standard temp/pressure)--the most stable molecule will always result.
An example:
On the reactants side the rightmost molecule (the aldehyde, ketone with a single hydrogen attached to carbonyl carbon) is subject to attack from the molecule on the left--much as in the acetone + water reaction above.
You'll notice that in one product (syn) the OH (alcohol) has a solid line and so does the CH3 group attached to the *new* central carbon. this means that they both "face" the same way. In the anti product the OH has a dotted line and the CH3 group still has a solid one--this means they point in opposite directions.
In this case, the anti product is favored--because the steric strain is lower when the constituents point in opposite directions versus pointing at each other. Thermodynamically speaking, the anti product is more stable (and for most reactions the anti product is always the more stable one for exactly the same reason).
Reactions can also be done under kinetic conditions, but by and large anything we'll do with canna chemistry will be concerned with thermo.
You can choose to believe me or not, but I promise you I'm not blowing smoke up your ass. I know what the fuck I'm talking about. Not only do I do this for a living, but it is my absolute joy to do so. I love this stuff, and have spent A LOT of time with it.
This is a reactive molecule--I mean you've now seen what it does with water (which I GUARANTEE is in your extract material). So there goes at least one molecule you didn't have before that you create during your extraction, if it does this with water and you have in your extract mixture molecules which are THOUSANDS OF TIMES MORE REACTIVE (and you do) you can be
guaranteed that you will be performing a myriad of side-reactions during this extraction. The products from those side reactions may then go on to do other reactions and so on and so forth. In the end you will have absolutely no idea what you're smoking.
I really just want to run an acetone extraction, run a BHO--and then take the results in to the NMR, so that I can convince you that acetone reactions are producing a shitload of new products. Unfortunately I cannot do this for fear of jail--but I hope that my expertise will be enough for you, that's the best I can do.
One last question:
How's the geminal-diol smoking?
:)
As a final plea--please understand that there is a reason chemistry labs the world over use acetone to clean their glass. It not only works well as a solvent--but reacts with anything left over in a vessel changing its state to something which can be washed out.
I have seen with my own eyes acetone destroy and eat away at a compound which concentrated sulfuric acid couldn't touch or clean away.
Please understand that from a chemistry perspective this is a big deal. Sulfuric acid destroys EVERYTHING.
Usually when cleaning lab glass I'll start with ethanol, graduate to soap and water, and if all else fails I'll bring the acetone in. Sometimes I've got to use a strong acid or base for certain molecules which only respond to these treatments--but for the most part acetone will knock it the fuck out,
no matter what it is.
This might not be an absolute recipe for disaster--but it's certainly a recipe for something other than
only pristine grade AAA cannabis extract.
Thing is, dude, I don't even have to get very advanced to understand that what I'm telling you is the truth. This is year one organic chemistry. This is like the first 4 weeks of material in any chemistry major. I'm about 7 years removed from that at this point--and easily like 4000 hours in the lab. It's also worth mentioning that in all of the myriad of chemistry specializations--this analysis falls squarely into my wheelhouse. I am concerned highly with predictive chemical reactivity in organic reactions.
I am an organic chemist who works mostly on catalysis--which requires an extensive knowledge of and ability to predict reactivity. That's essentially
all I do, in fact.
If you won't take it from me, you won't take it from anyone else here--so I figured I had to try.
