Unbelievably I just happened to stumble across a reference which uses acetic anhydride in a tertiary amine at 0'C to dehydrate a nitroaldol to the corresponding nitroalkene.
See: J. Org. Chem., Vol. 53, p2147, 1988 compound (
Now we know for a fact that acetic anhydride definitely won't acetylate the nitroaldol. Bring on the acyl chlorides!!!
Rh: I have seen a few reductions of mandelonitrile and its esters in the literature over the years. They were mostly catalytic hydrogenations and used plenty of sulfuric acid in combination with an alcoholic solvent. My thoughts on the CTH are if it can run in the presence of H2SO4 than it will probably do the trick for sure, however I have never seen a successful CTH in the lit. which used strong mineral acid as a reactant.
Perhaps mandelonitriles will reduce under standard CTH conditions and not require added acid, who'll be the first to find out?