When running a nitroaldol henry rxn on a 2,5-dialkoxy-4-alkylbenzaldehyde, what contribution in terms of yield do different bases bring? How important is the amount of water in the reaction, is using an anhydrous base truly nescessary? ammonium acetate is frequently used, preparation of the above from NH3/GAA should be easy enough, but what effects would using say, tertiary amine bases, other NH3 salts, such as the formate, etc have on the yields? I am aware that the presence of some H2O encourages the formation of the desired nitroalkene, rather than the beta-OH compound.