[discodermolide]

Lots of info there.
Why not try the extraction at a higher temperature? Perhaps the oily product will dissolve and then you can separate the layers and it will then crystallise.
pH6.3 in the first experiment, maybe you need to stick to that?
Try a different extraction solvent, isopropyl acetate for example.
Why are you getting so much variability, 30% and 60%, what was different about the two extractions?
As to the oil you have now. Dissolve in hot EtOAc and filter, cool and crystallise? Would not use MeOH as it is difficult to get rid of it, it also tends to give you sticky oils/solids.
Can't think of anything else ATM. Brain cell not up to working speed yet, not enough coffee and nicotine.

[Babcock_Hall]

One of the products was BOC-lysine-isonicotinamide, and the other one was BOC-ornithine-nicotinamide (I think that this is the one where the first ethyl acetate layer had a 0.6 to 1.0 mole ratio of product to 4-nitrophenol).  We had a better idea of how much of the latter material we had, because the former material was inherited from a previous student.  Also each student might have used slightly different technique with respect to the separatory funnel, but I believe that both shook for one minute.