621-61-4Relevant articles and documents
Synthesis of glycerol monostearate over K2CO3/γ-Al2O3 catalyst
Zhou, Lu,Gu, Yi,Hong, Mei,Xiao, Guomin
, p. 458 - 462 (2015/01/30)
The synthesis of glycerol monostearate by transesterification of methyl stearate with glycerol can be carried out in the presence of basic catalyst. The absence of solvent in the reaction system would result in a low conversion of methyl stearate as a consequence of low miscibility between reactants. The addition N,N′-dimethyl formamide as solvent improved the activity of the catalyst and selectivity to glycerol monostearate. Different K2CO3-containing γ-Al2O3 catalysts were made and used in the reaction. The results showed that catalyst with higher basicity could lead to better reactant's conversion but poorer selectivity to glycerol monostearate and the optimal load of K2CO3 inducing the highest yield to glycerol monostearate was 20 % mass fraction of γ-Al2O3 supporter. At a glycerol/methyl stearate ratio of 6:1, 165°C, 2 wt. % catalyst amount, a yield of 82.21 % of glycerol monostearate was achieved after 5h.
Optically active monoacylglycerols: Synthesis and assessment of purity
Chen, Chao-Yuan,Han, Wei-Bo,Chen, Hui-Jun,Wu, Yikang,Gao, Po
, p. 4311 - 4318 (2013/07/26)
Despite their simple structures, synthesis of 1(or 3)-acyl-sn-glycerols remains a challenge that cannot be ignored because of facile acyl migrations, which not only complicate the synthesis but also make direct GC or HPLC analysis unfeasible. Assessment of the optical purity of monoacylglycerols has, to date, relied almost exclusively on specific rotation data, which are small in value and thus insensitive to impurities. Now, a simple means to "magnify" the small specific rotations has been found, along with practical methods for the measurement of both 1,2-and 1,3-acyl migrations, which offer a convenient and straightforward alternative to Mori's NMR analysis of Mosher esters. With the aid of these methods, a range of conditions for deacetonide removal were examined en route to the synthesis of two natural monoacylglycerols. Refined hydrolysis conditions, along with useful knowledge about the solubility and reactivity of substrates with an ultra long alkyl chain are also presented. Copyright
Design of well balanced hydrophilic-lipophilic catalytic surfaces for the direct and selective monoesterification of various polyols
Kharchafi, Ghizlane,Jerome, Francois,Adam, Isabelle,Pouilloux, Yannick,Barrault, Joel
, p. 928 - 934 (2007/10/03)
The transesterification process is a well known reaction of organic chemistry. However, the monoesterification of unprotected polyols such as glycerol or sucrose is much more complex and the design of selective catalysts is becoming a huge challenge in order to avoid many protection and deprotection steps, harmful for the cost and the environmental impact of the resulting process. In this study, we showed that the control of the hydrophilic-lipophilic balance of heterogeneous catalysts is a crucial key in order to tune both the catalyst activity and the monoester selectivity. Indeed, whereas homogeneous guanidine led to low selectivity toward monoesters, its anchorage on a hydrophilic solid support such as silica allowed us to prepare two basic hybrid organic-inorganic materials able to selectively afford monoesters in high yield and in an environmentally-friendly process, at low temperature and starting from an equimolecular mixture of unprotected polyols and various fatty methyl esters. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
