We used d6-acetone as our NMR solvent for the silica-purified material. In retrospect my choice of solvent was not ideal; residual water is in the vicinity of the acetyl methyl groups, and the phenolic-OH signals were not strong. There was a huge roll with an integral of less than one that may or may not have been a phenolic -OH. The carbon NMR was a cleaner experiment; I have only glanced at it, but there is no sign of either carbon of an acetyl group. Tentatively, I would say that the method was successful. We may make up a sample in a different NMR solvent, such as DMSO. Chloroform would be a challenge, but we might be able to get enough material into solution for 1H NMR only. Obtaining MS data is not trivial for us right now, but it may become much more routine in a few months.
Thanks to all. Chemical Forums is a great resource for us!