At the start of my PhD, my supervisor gave me a project in which I would try to do a ring opening of sucralose using periodate to get a tetra-aldehyde product.
Molecular structure of Guar gum
The idea was to optimize this process and then to transfer these same conditions to convert guar gum to its tetra-aldehyde, convert the aldehyde groups to alkynes by a Corey–Fuchs reaction and then do click chemistry (copper catalyzed azide-alkyne cycloaddition) with a variety of azides in order to functionalize guar gum.
Looking back on it now it seems a bit far fetched. I gave it a try but I eventually found my way into another project involving isocyanates and hydantoins. To begin my investigation, I carried out a solvent survey of sucralose and guar gum. The results, posted below, reminded me that carbohydrates really don't dissolve in much.
Solubility of sucralose and guar gum in selected solvents
While I didn't get any further than this, the next step would be to try blends of water with organic solvents. I would also like to try cyclohexanone.
I have found that researchers in many synthesis labs are unaware that dimethylformamide (DMF) can be removed by a rotary evaporator. Providing the product compound is not heat sensitive, removal by evaporation is a much better option than a liquid/liquid workup which would waste a lot of solvent.
A 100 mL non-reversible splash-guard
To rotavap DMF, Dow Corning high vacuum grease must be freshly applied to the joins and Keck clips used to hold the flask onto a non-reversible splash-guard. With the water bath at 55 °C the vacuum will need to be lowered to 25 Torr; at 70 °C the required vacuum is only 25 Torr.
A 100 mL pre-weighed flask and a 500 mL non-reversible splash-guard attached to a rotary evaporator
The utility of the non-reversible splash-guard is not so much the prevention of mess or loss from bumping, rather that it reduces the distance that the DMF fumes must travel to be removed from the flask. This is because DMF vapours will quickly condense as they get further away from the flask which is in a hot water bath (55-70 °C) and come into contact with the glass parts of the rotavap that are at room temperature (~20 °C). Shortening this distance makes DMF removal from a mixture much easier.
Note the shortened distance that the DMF vapours will have to travel before condensing when using this splash-guard. It is ~4 cm less.
Removing DMF is slow and is prone to bumping so only lower the pressure gradually. You might want to leave a note for your co-workers saying that you are removing DMF and go for a cup of coffee.