I attempted to convert methyl 4,4-dimethoxybutanoate into its aldehyde using acid hydrolysis for subsequent chemical synthesis. I followed the protocol in Drinan, Martin A. and Lash, Timothy D. Journal of Heterocyclic Chemistry, 31(1), 255-7; 1994. https://doi.org/10.1002/jhet.5570310144
. This protocol was quite detailed in the volumes of solvents used in the extraction, and I tried to follow it very closely. Nevertheless my recovery was lower than the published value (which I seem to recall was 87%). I think that one reason my recovery was low (roughly 30%) is that the product is more volatile than I thought it was. I lost some mass during 30 minutes of (semi)high vacuum. I even noticed a slow loss of mass when I subsequently used a stream of nitrogen (I thought that I was removing DCM from the extraction after the hydrolysis, but now I think that most or all of the DCM was already gone).
Should I try a different protocol for hydrolysis of the acetal, or would it be better to try an entirely different approach? One possibility is to start with the 4-hydroxy ester and oxidize it under mild conditions to the aldehyde. I have found some oxidations leading to the same product via SciFinder, but I have not attempted to evaluate them.
One thing that I would do differently is to take an NMR right after the rotary evaporation. Then I would use nitrogen and follow the loss of any remaining DCM by NMR. Tedious perhaps, but better than losing product.