Participation of a Neighboring Carboxyl Group in Addition Reactions. I. The Mechanism of the Reaction of Bromine with γ,δ-Unsaturated Acids and Esters1

1953 ◽  
Vol 75 (5) ◽  
pp. 1044-1047 ◽  
Author(s):  
Richard T. Arnold ◽  
Marcello de Moura Campos ◽  
Kenneth L. Lindsay
Keyword(s):  
Addition Reactions ◽  
Carboxyl Group ◽  
Mechanism Of The Reaction

scholarly journals Cephalexin Degradation Initiated by OH Radicals: Theoretical Prediction of the Mechanisms and the Toxicity of Byproducts

2021 ◽  
Author(s):  
R. Masmoudi ◽  
S. Khettaf ◽  
A. Soltani ◽  
A. Dibi ◽  
L. Messaadia ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Theoretical Prediction ◽  
Hydroxyl Radical ◽  
Density Functional ◽  
Aquatic Organisms ◽  
Addition Reactions ◽  
Oh Radicals ◽  
Functional Theory ◽  
Radical Attack ◽  
Mechanism Of The Reaction

Abstract In this work, density functional theory is used to study the local reactivity of cephalexin (CLX) to radical attack and explain the mechanism of the reaction between CLX and hydroxyl radical attack leading to degradation byproducts. The reaction between •OH and CLX is supposed to lead to either an addition of a hydroxyl radical or an abstraction of a hydrogen. The results showed that the affinity of cephalexin for addition reactions increases as it passes from the gas to the aqueous phase and decreases as it passes from the neutral to the ionized form. Thermodynamic data confirmed that OH addition radicals (Radd) are thermodynamically favored over H abstraction radicals (Rabs). The ecotoxicity assessments of CLX and its byproducts are estimated from the acute toxicities toward green algae, Daphnia and fish. The formation of byproducts is safe for aquatic organisms, and only one byproduct is harmful to Daphnia.

Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Water Molecules ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

Thia-Michael Addition Reactions in Water Using 3-[Bis(Alkylthio) Methylene] Pentane-2,4-Diones as Odorless and Efficient Thiol Equivalents

2007 ◽  
Vol 4 (4) ◽  
pp. 281-284 ◽  
Author(s):  
Yanyan Chai ◽  
Dewen Dong ◽  
Yan Ouyang ◽  
Yongjiu Liang ◽  
Yan Wang ◽  
...  
Keyword(s):  
Michael Addition ◽  
Addition Reactions

Acetolysis of 4β-methanesulphonyloxy-6β,7aβ-cyclo-B-homo-5α-cholestane

1979 ◽  
Vol 44 (11) ◽  
pp. 3308-3320 ◽  
Author(s):  
Ladislav Kohout ◽  
Jan Fajkoš
Keyword(s):  
Mechanism Of The Reaction

Synthesis of 4β-methanesulphonyloxy-6β,7aβ-cyclo-B-homo-5α-cholestane is described. During its acetolysis a kind of conjugative stabilization of the carbocation formed was observed. The mechanism of the reaction is discussed.

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