Hydration of the Carbonyl Group. A Theoretical Study of the Cooperative Mechanism

1995 ◽  
Vol 117 (15) ◽  
pp. 4240-4260 ◽  
Author(s):  
Saul Wolfe ◽  
Chan-Kyung Kim ◽  
Kiyull Yang ◽  
Noham Weinberg ◽  
Zheng Shi
Keyword(s):  
Carbonyl Group ◽  
Theoretical Study ◽  
Group A

INFRARED SPECTRA OF 2,6-DIMETHYL-4-PYRONE COMPLEXES

1961 ◽  
Vol 39 (6) ◽  
pp. 1184-1189 ◽  
Author(s):  
Denys Cook
Keyword(s):  
Complex Formation ◽  
Oxygen Atom ◽  
Carbonyl Group ◽  
Lewis Acid ◽  
Frequency Band ◽  
Infrared Spectra ◽  
Donor Site ◽  
Carbonyl Oxygen ◽  
Acid Strength ◽  
Group A

The infrared spectra of 2,6-dimethyl-4-pyrone in solution, and in complexes with HgCl2, ZnCl2, BF3, SbCl5, and HBr have been recorded. A band at 1639 cm−1 in the free pyrone moves to progressively lower frequencies in the complexes as the Lewis acid strength increases, identifying this band as the carbonyl stretching frequency and the donor site as the carbonyl group. A higher-frequency band, at 1678 cm−1 in the free pyrone, moves to lower frequency on complex formation, but to a much smaller extent, and is to be identified with a stretching mode of the ring. The site of protonation in 2,6-dimethyl-4-pyrone salts has been unequivocally shown to be the carbonyl oxygen atom.

scholarly journals Regioselectivity of glycosylation reactions of galactose acceptors: an experimental and theoretical study

2019 ◽  
Vol 15 ◽  
pp. 2982-2989 ◽  
Author(s):  
Enrique A Del Vigo ◽  
Carlos A Stortz ◽  
Carla Marino
Keyword(s):  
Molecular Modeling ◽  
Theoretical Study ◽  
General Trend ◽  
Relative Reactivity ◽  
Protecting Groups ◽  
Equatorial Orientation ◽  
Modeling Approach ◽  
Group A ◽  
The Difference ◽  
Glycosyl Donors

Regioselective glycosylations allow planning simpler strategies for the synthesis of oligosaccharides, and thus reducing the need of using protecting groups. With the idea of gaining further understanding of such regioselectivity, we analyzed the relative reactivity of the OH-3 and OH-4 groups of 2,6-diprotected methyl α- and β-galactopyranoside derivatives in glycosylation reactions. The glycosyl acceptors were efficiently prepared by simple methodologies, and glycosyl donors with different reactivities were assessed. High regioselectivities were achieved in favor of the 1→3 products due to the equatorial orientation of the OH-3 group. A molecular modeling approach endorsed this general trend of favoring O-3 substitution, although it showed some failures to explain subtler factors governing the difference in regioselectivity between some of the acceptors. However, the Galp-(β1→3)-Galp linkage could be regioselectively installed by using some of the acceptors assayed herein.

Chemical functionalization of BN graphene with the metal-arene group: a theoretical study

2012 ◽  
Vol 22 (18) ◽  
pp. 9343 ◽  
Author(s):  
Jing-xiang Zhao ◽  
Yuan-yuan Yu ◽  
Yu Bai ◽  
Bin Lu ◽  
Bing-xing Wang
Keyword(s):  
Theoretical Study ◽  
Chemical Functionalization ◽  
Group A

Anion-Binding Properties of the Tripyrrolemethane Group: A Combined Experimental and Theoretical Study

2007 ◽  
Vol 13 (2) ◽  
pp. 657-665 ◽  
Author(s):  
Chagit Denekamp ◽  
Kinga Suwinska ◽  
Hussein Salman ◽  
Yael Abraham ◽  
Yoav Eichen ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Anion Binding ◽  
Binding Properties ◽  
Group A

CYCLIC COMPOUNDS CONTAINING A CARBONYL GROUP; A MECHANISM FOR THE FORMATION OF PYRYLLIUM SALTS FROM 1,5-DIKETONES

1933 ◽  
Vol 9 (6) ◽  
pp. 574-582 ◽  
Author(s):  
C. F. H. Allen ◽  
H. R. Sallans
Keyword(s):  
Carbonyl Group ◽  
Methyl Ether ◽  
Ring Closure ◽  
Closed Ring ◽  
Second Mode ◽  
Ring Structures ◽  
Group A ◽  
Plausible Mechanism ◽  
Cyclic Compounds

In the presence of alkali, cyclohexanone and its homologues add to chalcones to form either semicyclic diketones or dicyclic keto-alcohols; the latter contain a carbonyl bridge, and the former can be converted into closed ring structures and dehydrated to form substances having a carbonyl bridge. In these dicyclic ketones the bridge is not removed by heating, in contrast to the behavior of certain other compounds having a similar ring system.A second mode of ring closure gives rise to pyryllium salts; the isolation of a methyl ether has made it possible to devise a plausible mechanism for this hitherto obscure reaction. Four varieties of salts are described, the perchlorates being obtained by a different procedure than that previously employed.

Theoretical study of neighboring carbonyl group participation in the elimination kinetics of chloroketones in the gas phase

2010 ◽  
Vol 24 (3) ◽  
pp. 229-240 ◽  
Author(s):  
José R. Mora ◽  
Jesús Lezama ◽  
Edgar Márquez ◽  
Luz Escalante ◽  
Tania Córdova ◽  
...  
Keyword(s):  
Gas Phase ◽  
Carbonyl Group ◽  
Theoretical Study ◽  
Elimination Kinetics ◽  
Group Participation ◽  
Kinetics Of
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