Transesterifications over titanosilicate molecular sieves was written by Srinivas, D.;Srivastava, R.;Ratnasamy, P.. And the article was included in Catalysis Today in 2004.Quality Control of malonic acid dibutyl ester This article mentions the following:
Titanosilicate mol. sieves (TS-1, Ti-MCM-41 and amorphous TiO2-SiO2) catalyze transesterification reactions. Acidity measurements (pyridine adsorption-IR and NH3-TPD) reveal the presence of only weak Lewis acid sites. Catalytic activity parallels the acid strength and increases in the order: TS-1<Ti-MCM-41<amorphous TiO2-SiO2. TS-1 efficiently catalyzes the transesterification of only linear esters (Et acetoacetate and di-Et malonate), but fails for cyclic esters like propylene carbonate. Ti-MCM-41 and amorphous TiO2-SiO2 are superior for the latter. The catalysts could be recycled without any loss in activity/selectivity. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Quality Control of malonic acid dibutyl ester).
malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Quality Control of malonic acid dibutyl ester
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics