The selective esterifications of L-malic, L-tartaric and citric acids with tetramethoxysilane Si (OMe) 4, in methanol (MeOH) have been demonstrated for the first time. The interactions between these acids and Si (OMe) 4, and also between oxalic acid and Si (OMe) 4, were investigated using 1H, 13C and 29Si solution phase NMR, and electrospray mass spectrometry (ES-MS). Si (OMe) 4 acts as a catalyst/reagent in the selective esterification ...