hypervalent_iodine

So, did you actually read the 'NO, you can't make sodium' thread? Because you should.

Yes, I mentioned lyophilising in my first post. We don't have a freeze drier in our lab I guess I'm just pedantic. Unless it's a carry through, I like to have all solvent goooonnnneee.

Read the thread

Okay, then HCl and liquid ammonia will work. Just be careful. Read the MSDS's and do it somewhere with good ventilation.

EtOAc is the devil. When I worked with sugar based compounds last year, I spent most of my time trying to get rid of the stuff. Working with sugars meant I also couldn't heat my product above 30 degrees C, lest I make toffee. Most of my products took a few days under high vac before they would even think about crystallizing out.

I would have drawn it like this: I personally think that drawing the carbonyl is easier in a lot of cases than is writing CO. Plus, it makes drawing ring structures a bit easier (for me at least). Groups such as Et, CO2Et, Ph, etc. I tend to write, depending on what I'm doing. If I'm drawing a mechanism, I draw out the pertinent bits of the molecule that I might otherwise write in short hand. If it's for a paper, I do short hand for protecting groups and typical reagents only. As for the phenyl group problem: I personally don't like the circle in the middle business and I will always draw the bonds. It's a matter of preference I suppose. Another way to represent a phenyl group is with the symbol, Ø. It obviously doesn't to the case above. It's more if the phenyl group is a substituent.

What's wrong with dry ice? It's by far the safest option that I can think of.

What do you need the crystals for? Often, compounds will exist as liquids at room temperature. It's just how it is really. If you were expecting crystals and you aren't getting them it may be that you have solvent contaminating your product. Some solvents can be quite tricky to get out. My advice would be to pump it down as much as you can on a rotary evaporator (you may need to put in a water bath at about 45 degrees C) and then put it under a high vacuum or lyophiliser. A simple proton NMR should tell you if solvents are the problem. Otherwise, your product may just have a low melting point. Nothing wrong with that, unless of course you wanted to get an X-ray crystal structure. Edit to add: your product may be hydroscopic (I've not looked into it for your exact case). If you leave it under high vac for a while, you may see condensation on your gooseneck connector. A quick treatment with a heat gun will get rid of that. Keeping water out will probably involve a super seal on your flask, parafilm and a fridge. Or transfer it to a dry, glass vial and parafilm around the lid before putting it in the fridge.

Nabilesmail, As this is a homework question, I will not give you the answers. I can assist in understanding the concepts, so if you could perhaps tell me what it is you aren't getting specifically, I (or the others on the site) could assist?

We have to wear gloves all of the time when handling chemicals here. Most people I've encountered aren't complacent enough to suppose that gloves are a be all and end all in terms of protection - with the exception of first years perhaps. Also, they let first years in chemistry labs there? My goodness. That's unheard of here! I had so much trouble finding a spot in a lab for the summer following my first year that I ended up in a biology lab doing PCR for weeks on end.

Tisk tisk. Whatever would occupational health and safety say of that!?

Fantastic. And a 100% safe mistake to make!

It is often the case that text books either gloss over complicated processes either because the mechanisms are not fully understood or because the target audience for the books themselves is not at a level at which a complicated explanation is necessary. For undergraduate, asking a student to just accept that this thing does that is quite common place, because of time restraints or because it is simply to complicated for their level of education. University level text books will generally assume no more than a high-school equivalent knowledge (sometimes, they won't even assume that), so no, the things you mentioned are not things you should already know. If you have questions like that, the best place to search for answers is by reading scientific literature. You can search topics on Google scholar if you do not already have access to a scientific journal search engine. Pubmed is another site that may provide a wealth of knowledge (although not all of it is accessible). Or, you could always ask specific questions here. There are a lot of biologists, chemists (such as myself), physicists, etc. who would be more than willing to help understand

I have my reservations about him. I mean, if you look at his wiki article and scroll to the 2nd last paragraph (end of the Woodward-Hoffman rules), there is a clear implication that he was somehow involved in Woodward's death. Scandal!

Well gosh, let's not stop at current events.

farmboy, I'm not sure I quite understand what you're attempting to say, so please forgive any misinterpretations. I don't think the definition of homosexuality vs. heterosexuality is so-much the issue here. Or at least, the issue does not appear to have been raised within the context of this thread (until now). Can I ask what it is about my previous post that you do not agree with? It wasn't made particularly clear to me where there was disagreement on your part, judging by your post.

This thread has something of a surfer tone to it. You're making chemistry sound deceivingly casual.

Ah, I see it. I had considered that something along those lines may be implicated, but then I couldn't be bothered to model it in my head.

At a guess, I would say it is to do with stereoelectronics. The cyclopentane with the t-Bu group on it will be feeding more electron density towards the migratory carbon than will the cyclopentene, which would of course stabilise the transition states to a higher degree during the migration. Perhaps I am wrong on that assumption though.

I agree with Ringer. You do not ever need to memorise the periodic table. The stuff they teach in the beginner chemistry course where I am includes: States of matter What is an atom? (protons, neutrons and electrons) Orbitals How to calculate valence electrons How to read the periodic table (I.e. Where the transition metals are, electronegative trends, etc.) The concept of a mole and other stoicheometric relationships Different types of compounds (fatty acids, carbohydrates, etc) Ionic bonding Covalent bonding Hydrogen bonding Van der Waals forces London dispersion forces The concept of pH Density Pauli exclusion principle Aufbau principle That other principle related to the above two and whose name escapes me That's all I recall from tutoring it a while back. They may have also learnt things pertaining to VESPR and Lewis diagrams, hybridization, transition metals, electrochemistry, equilibrium calculations, more complicated pH stuff, acid dissociation, phase diagrams and the associated maths, ideal gas laws, Gibbs free energy, entropy, enthalpy, molecular geometry, crystal field theory, solubility, reaction rate kinetics, quantum numbers and basic organic chem. I would focus on that top list before hazarding a go at the rest though. Anyway, I think that's most of it off the top of my head. Apologies if I missed something.

It will do that. Even more horrible is DCM and contact lenses. The vapours will react with the polymers in the lenses and cause them to adhere to your eyes.

Are you given the structure of a carbohydrate and asked to determine stereochemistry in terms of ® and (S) or are you also being asked to determine if it is a D or L sugar and what the name of it is, etc.?

I don't know about farmboy, but Horza and myself are both PhD level synthetic, organic chemists. I tend to think that we have more than just a bit of an idea with what's involved in structural elucidation. It really isn't an easy task, even for those who have a PhD and have completed post-doc projects in the area. If you don't even know if this 'thing' it secrets is a relatively simple chemical or a protein my first question would be, how will you even know it's what you want (presuming you somehow manage to isolate it)? Isolating compounds can be a painful process as it is, even when you know exactly what you are looking for - which you apparently do not. Chances are, your organism secrets hundreds or more chemicals, all of which you would have to sift through and test individually to find exactly what you are after. Could you send to a lab to get tested? Probably not. I wouldn't think that any labs capable of such a thing would be willing cooperate with single individuals not associated with a research group, industry, etc. I could be wrong on that though. Doing this sort of thing 'at home' is not sufficient if you intend to market your end product. You need a controlled laboratory environment for every step of the process if you don't intend to have your results thrown out and discarded entirely. This takes me back to the point on having access to equipment. If you do not have access to NMR, HPLC, IR, mass spec, etc. etc., you will not be able to do this. As for your organism. You need to ask yourself a few questions. How hard is to to obtain your organism? How much maintenance is required and what sort of equipment do you have to have to be able to cultivate them? We cannot answer these questions without knowing what the organism is, as every organism requires a different environment for optimal growth. You should find specifics in the literature though. I am not saying these things to simply dampen your spirits and nor am I making this sound harder than it is. In fact, that you would think we are doing that tells me you do not have the experience needed to attempt this. In any case, we are trying to be a bit realistic about your idea. It could be a fantastic idea, I don't know, but it is unfeasible for someone with little experience in the field and for someone with no access to the right equipment. Finally, if I may ask you, are you trying to find the active chemical/protein/whatever responsible for the claims that hookworms can eliminate the affects of allergies? Because that's what this sounds like. I think it's called Helminthic therapy...

I in fact said nothing about it being akin to learning a language or otherwise, merely that I agreed with farmboy on the point of developing chemical intuition being far more advantageous than memorising reactions.

While your bit about learning the structures of functional groups, etc. over their names may be true, it certainly will not be helpful in an exam type situation and even less helpful when you are trying to communicate to your colleagues (or when they are trying to communicate with you). I 100% agree with you when you said that learning why reactions occur they way they do is much more useful than simply memorising a reaction. There are simply too many reactions in organic chemistry for anyone to be able to memorise them all. Understanding why reactions occur the way that they do allows you develop a certain type of chemical intuition, which is an invaluable trait to have to a synthetic organic chemist such as myself.