inspired durch no1uno´s great idea for enantioselective P2P reduction, i researched a bit and found lots of material, experiments so simple that students will do them at university and else, a example (the third) is attached.
In general, living yeast will reduce ketones and ester of ketocarboxylic acids to their alcohols, in high enantiopure output to the corresponding dextro isomeric alcohol leaving nearly every other group or chirality completely untouched. So I thought a bit more where it could have uses for the clandestine chemist and some of the better are:
- If one has racemic RS-methcathinone, it would be reduced to 1S,2S-(pseudo)ephedrin (natural occuring d-pseudo) and 1S,2R-ephedrin (the unnatural d-ephedrine)
- Or if one would use several of those stimulating cathinones, like ethylcathinone or those fluorocats, they would reduce to a very convenient ephedrine to use for novel N-4-dimethylaminorex compounds?
- And the most fascinating of course the P2P reduction itself, should bee very high yielding as acetophenon reduces in a yield over 80% in an enantiomeric excess of nearly 90% to dextro-"acetophenol" in less than 100 hours reaction time... similiar success with P2P here can be expected and every cook will more likely become a brewer, even more as its the case with the a lot better known l-PAC fermentation

I for myself will give these reaction a try soon using another substrate, and a easy way to monitor the enantiopurity too because my substrate will be racemic carvone ive made out of d-limonene. It has become racemic for sure during the process, as it smells now like mint and caraway instead of the even more pleasant citric smell of oranges of d-limonene before. the reaction product there should only carry one of these smells but i dont know sure its l-carveol and not d-carveol i get but this will show it easy and useful too, pretty cool

What do you think? theres definitely much potential for us to discover, i mean, its a 100% OTC thing really cool find that no1one made there, isnt it

the latter attachements is a write up for students but it is in german, but in a rather more practical speech written that this from orgsyn ive posted also in the P2Pol topic:
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv7p0215
 

yeah ive read that too but nobody has ever thought about potential uses for the clandestine chemist! no1uno had brought this idea up as totally novel process and it seems it is indeed a very good and high yielding practical one that will undoubtfully work!
and Ive found out its possible to yeast-reduce the precursor to racemic (meth)cathinone before sn2-amination, if I am not totally wrong this would lead to only 1s,2s-d-(nor)pseudoephedrine only!
that carvone I am about to reduce is of course also a precursor of some sort as the resulting (+)-p-2,8-menthadien-1-ol oder carveol is an enantiospecific high yielding building block for cannabinoids

Soooo... if one would look through the literature how these reactions would be carried out using standard chemicals as reducing agents (no isomer preferred then of course), one would notice that for especially the three by me mentioned reactions need stuff like NaBH4, Pd/C, LiAlH4, Ni/Al (raney), and so on....
If these reagents are more easy to acquire then it is yeast for some... so he should stick to the chemical way... if not yeast will do too!

It just sucks that yeast cannot reduce imines.... imagine a tryptophol producing fermentation, acetaldehyde gets produced. tryptamine is the intermediate for tryptophol.... go on genetic engineers!

DET producing yeast would be the fucking BOMB!!!

Yeast really has become like my favorite plant/animal/flavor/beer/fungus
 

wow lugh thank you!
They even made amphetamine using yeast, please tell me where have you found this little treasure? unbelievable cool really  
yeah i forgot to mention in this thread this stuff reduces nitroalkenes to nitroalkanes which is another clandestine application of yeast, but so is l-PAC.
In this thread ive meant more specific the ketone/carboxylic acid ketoester  reduction. But it seems the potential substrates of use are nearly starved with these substrates. 

its too bad this archive has no search function, really!
its the same like here, some topic shows up, and only 2-3 posts after the first it goes completely offtopic, usually even as useful, mostly even more but that makes it nearly impossible to find something of use, i mean, just try to google such things.

Edit: This chinese p2p->d-amphetamine paper uses even a tosylate for amination!! this implicates we as community are at least braintrust-worthy as these chinese guys since the we figured it out mainly ourselves, wow 
Edit2: They use only 400ml water per 5g of P2P! this is a lot more compared to the more toxic benzaldehyde.... wow... and get 4,5g d-P2P-ol of it even!
Damned this is the most attractive biosynthesis ive ever stumbled upon! and less product to obtain from fermentation broth, i just wonder how much the amount of substrate can be increased for more yield per lesse volumen, if one uses alginate immobilized yeast cells...

Mg in MeOH reduces -C=C- as well.

The only reference I can find for this involves metallic magnesium activated by iodine reducing ene-amides, alpha beta unsaturated ketones, and peroxides.  If there is something I'm missing, please point me in the right direction

i was playing with yeast a bit, two hours ago dumped the yeast in its prepared solution, one hour later (so one hour ago) added some racemic carvone, and im very curious now, because it smells more mintier than before, i have expected that the minty scent will go away and instead the caraway smell will become more intense... ill wait till today evening and keep you updated about the smell of my culture then

nearly mintless in smell! Here are some more details, i used a 42g block fresh yeast. 80g fructose, 4-4,5ml mostly carvone containing oxidation product of limonene in 600ml water.
I will let it ferment till tomorrow then i try to extract out as much as i get but smells like a success up to now even if it seems im not so pleased by the smells as before, it really has some kind of cannabis reminding scent i would say

did you mean you used IPA to help your educt dissolving? IPA is a lot more toxic for yeast, but im not sure if I get what you mean? Or do you mean you used IPA as eluent?
confusion, confusion

hmmm... so you werent able to extract anything, or was it just precursor you could recover? i dont think i can be helpful much there, have not looked much into especially yeast mediated nitrostyrene reduction, and i have not found the reaction you referred to in the paper, what do they use there? Ethanol i would guess? Or maybe no solvent except water?
You shouldnt give the yeast reduction up so fast, if you can afford it maybe do a few smaller fementations using more yeast and i think you will have more success then soon. Its just the hardest part always to extract a fermentation, not the fermentation itself in my opinion                                                                                                                                                                                                                                                                                                                                                                                                                                                        

ive read it now, it uses completely different condition, and nothing to feed the yeast? also they use dried yeast, it is only partial comparable to the conditions used in ketone reduction, the enzyme ADH which is the working principle behind the ketone reduction will work under a lot of conditions, it is active in an acidic or a weakly basic millieu as well.
the experiment using carvone ive made, is only considered as a funny thing to try out and so i have not manipulated the conditions in any direction, the ph will go up during fermentation anyway which is favored for the enzyme ADH, and the temperature was high enough as it is summer now. I did not wanted to do a very serious experiment, as you can see i just had the carvone here, and no use for it so i just dumped everything together, this was not the first fermentation reaction i have done but the first yeast reduction out of pure fun so theres no need to be sarcastic like this:

And if you finally read the article I posted you will see that yields depend on ph, substituents, temperature, and NASDAQ index.

I have just followed the very general procedure for reduction of ethylacetoacetat, except without taking much care on the temperature. I would have been satisfied even without working it up, just to notice that the smell is changing.

Also, what is light petroleum exactly?

Maybe Petroleum ether/ Naptha.