Role of Metallic Cation in Aldol Condensation of Metallo Esters with Acetophenone to Form β-Hydroxy Esters. Reversal to Claisen Acylation or Self-condensation of the Ketone1

1953 ◽  
Vol 75 (19) ◽  
pp. 4756-4759 ◽  
Author(s):  
Charles R. Hauser ◽  
W. H. Puterbaugh
Keyword(s):  
Aldol Condensation ◽  
Metallic Cation ◽  
Hydroxy Esters

Topography of the Free Energy Landscape on the Claisen-Schmidt Condensation: Solvent and Temperature Effect in the Rate-Controlling Step

2021 ◽  
Author(s):  
Nayara Dantas Coutinho ◽  
Hugo Gontijo Machado ◽  
Valter Henrique Carvalho-Silva ◽  
Wender A. Silva
Keyword(s):  
Free Energy ◽  
Temperature Effect ◽  
Strong Influence ◽  
Aldol Condensation ◽  
Energy Landscape ◽  
Bond Formation ◽  
Free Energy Landscape ◽  
Rate Controlling Step ◽  
Formation Step

Recent studies have assigned hydroxide elimination and C=C bond formation step in base-promoted aldol condensation the role of having a strong influence in the overall rate reaction, in contrast to...

X-ray microanalysis of calcium content in secretory granules of goblet cell of the rabbit oviduct

1990 ◽  
Vol 48 (2) ◽  
pp. 178-179
Author(s):  
Manuel Villalón ◽  
Dale E. Johnson ◽  
Pedro Verdugo
Keyword(s):  
Secretory Granules ◽  
Polymer Network ◽  
Calcium Content ◽  
Regulatory Peptides ◽  
Goblet Cells ◽  
Exocrine Secretion ◽  
X Ray ◽  
Metallic Cation ◽  
Secretory Products

Secretory granules have two ubiquitous features: they are acidic, and they contain a distinct combination of a two countercharged species: a polyanion, which is usually interconnected forming a polymer network, and a cation or polycation. In most endocrine cells the polyanion belongs to the chromogranin/secretogranin family of acidic proteins, while the polycation is usually the hormonal or transmitter species itself (amines, regulatory peptides, hormones), or else a metallic cation (Ca++, K+, Mg++)(Ann. Rev. Physiol 52:625,1990). In exocrine secretion, like in serous cells, the polyanic polymer network is made of proteoglycans and the shielding cations are a family of polycationic proteins that include lysozyme, lactoferrin, and antileucoprotease (Ann. Rev. Physiol. 52:97,1990). We have proposed that the role of cations or polycations in the granule is to facilitate the condensation of secretory products by screening the polyanionic charges of the secretory networks (Ann. Rev. Physiol. 52:157,1990). In goblet cells of the oviduct, the polyanionic polymers are mucins, while the correponding cationic species has not been identified. In this study x-ray microanalysis was used to determine the presence of a shielding cation(s) in secretory granules of goblet cells of the rabbit oviduct.

scholarly journals In situ ATR-IR studies in aqueous phase reforming of hydroxyacetone on Pt/ZrO2 and Pt/AlO(OH) catalysts: The role of aldol condensation

2018 ◽  
Vol 232 ◽  
pp. 454-463 ◽  
Author(s):  
Kamila Koichumanova ◽  
Anna Kaisa K. Vikla ◽  
Remedios Cortese ◽  
Francesco Ferrante ◽  
K. Seshan ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Aldol Condensation ◽  
Aqueous Phase Reforming ◽  
Ir Studies

Roles of ethanol and Si–OH in the aldol condensation of ethyl acetate over a Cs/SBA-15 catalyst

2021 ◽  
Author(s):  
Xiang Tian ◽  
Hengshui Tian
Keyword(s):  
Ethyl Acetate ◽  
Aldol Condensation ◽  
Ethanol Dehydrogenation ◽  
Negative Effect

The negative effect of ethanol dehydrogenation and role of Si–OH are explored in the aldol condensation of ethyl acetate.

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