[synthon]

I'm attempting the synthesis (hopefully) drawn below, based on a JOC paper (1992, p3916) which uses primary and secondary alkylamines, instead of IDA.  Those products simply precipitated from the aqueous reaction mixture, but this has not been the case when using IDA.  I'm thinking the reaction has not taken place, but I can't figure how to follow the reaction, outside of MS to detect if the product is present, or NMR to observe the unique hydroxyl-adjacent proton peak.  Neither are convenient. Nothing moves on TLC of course.

I am now thinking that protecting IDA may help the nucleophilicity of the amine? as well as possibly being able to use a less polar solvent?  Any suggestions to get this moving are much appreciated.

Also, this is my first post here, so if anything is incomplete or outside conventions, please don't hesitate to mention it.  Thanks in advance.

[Babcock_Hall]

I have seen two stable carbinolamines in the literature (both were seven-member rings, oddly enough).  The carbon atom is quite downfield, but I don't recall where the hydrogen ends up.  TLC should work, but you will need to find a decent solvent.  Amino acids often move in 70% ethanol, for example.  Egon Stahl's (now ancient) book on TLC has several systems that move amino acids; some acidic solvent systems and some basic.

[discodermolide]

I'm attempting the synthesis (hopefully) drawn below, based on a JOC paper (1992, p3916) which uses primary and secondary alkylamines, instead of IDA.  Those products simply precipitated from the aqueous reaction mixture, but this has not been the case when using IDA.  I'm thinking the reaction has not taken place, but I can't figure how to follow the reaction, outside of MS to detect if the product is present, or NMR to observe the unique hydroxyl-adjacent proton peak.  Neither are convenient. Nothing moves on TLC of course.

I am now thinking that protecting IDA may help the nucleophilicity of the amine? as well as possibly being able to use a less polar solvent?  Any suggestions to get this moving are much appreciated.

Also, this is my first post here, so if anything is incomplete or outside conventions, please don't hesitate to mention it.  Thanks in advance.

The bis glycine you call IDA is certainly going to be present as an internal salt. So you need to get below the isoelectric point,that is basic, before it will react with the aldehyde. So everything in the reaction mixture will be a salt of the carboxylic acids.
Under these conditions I think the aldehyde will polymerise and the desired reaction will not take place.
Is this product a known compound?
As for TLC, you will need an acetic acid/chlorofrom/methanol/water mixture to get these compounds to move. Experiment with the ratios, something like 85/5/9/1.

[synthon]

@disco, the product is not a known compound.  I would assume that the polymerized glyoxylic acid (GA) would precipitate from concentrated solution, which wasn't observed at high pH, but I could be mistaken.  Maybe adjusting the pH near 8-9 would allow for some overlap between the polymerised aldehyde and basic IDA, allowing the reaction to proceed?

Thanks to both for tips on the TLC. I'm assuming that a basic KMnO4 stain will do the trick, I'll run some trials.