The reaction of amines with conjugated dienes in the presence of alkali naphthalenide. A new synthesis of geranyl acetate

1974 ◽  
Vol 27 (3) ◽  
pp. 531 ◽  
Author(s):  
T Fujita ◽  
K Suga ◽  
S Watanabe
Keyword(s):  
Acetic Anhydride ◽  
Conjugated Dienes ◽  
Geranyl Acetate ◽  
Conjugated Diene ◽  
New Synthesis ◽  
Sodium Naphthalenide

Reaction of a conjugated diene with diethylamine using sodium naphthalenide in tetrahydrofuran gives a mixture of β,γ-unsaturated amines. From myrcene, N,N-diethyl-2-ethylidene-6-methylhept-5-enylamine, N,N-diethylnerylamine and N,N-diethylgeranylamine are obtained. Reaction of β,γ-unsaturated amines with acetic anhydride gives a mixture of β,γ-unsaturated acetates. From N,N-diethylgeranylamine, a mixture of neryl acetate and geranyl acetate is obtained.

scholarly journals Inhibition by heparin of Fe(II)-catalysed free-radical peroxidation of linolenic acid

1992 ◽  
Vol 286 (3) ◽  
pp. 717-720 ◽  
Author(s):  
M A Ross ◽  
W F Long ◽  
F B Williamson
Keyword(s):  
Linolenic Acid ◽  
Thiobarbituric Acid ◽  
Conjugated Dienes ◽  
Dependent Manner ◽  
Gamma Linolenic Acid ◽  
Conjugated Diene ◽  
Concentration Dependent Manner ◽  
Repeat Units ◽  
Molar Basis ◽  
Endogenous Antioxidants

Heparin, in a concentration-dependent manner, inhibited the generation of conjugated dienes and thiobarbituric acid-positive substances when incubated with Fe2+ and gamma-linolenic acid. In the conjugated diene assay, other glycosaminoglycans, on a molar basis calculated with respect to their respective hydrated disaccharide repeat units, were less effective than heparin. Heparin which had been re-N-sulphonated after removal of both N-sulphonates and O-sulphates, and heparin in which iduronate residues had been reduced to idose residues, were largely unaffected in their activity. Removal of both N-sulphonates and O-sulphates greatly reduced the effectiveness of the heparin. Analysis of the effects of heparin fragments generated by heparinase I treatment of heparin showed that depolymerization decreased the effectiveness of the heparin. It is possible that heparins and related strongly acidic polysaccharides may function as endogenous antioxidants, and that sequestration by them, or harmless oxidation by them, of ions such as Fe2+, contributes to their effectiveness.

Coupling of Propargylsilanes with Fischer Carbene Chromium Complexes: A New Synthesis of Conjugated Dienes.

ChemInform ◽  
2005 ◽  
Vol 36 (11) ◽  
Author(s):  
Paren P. Patel ◽  
Yixin Zhu ◽  
Lei Zhang ◽  
James W. Herndon
Keyword(s):  
Conjugated Dienes ◽  
Chromium Complexes ◽  
Fischer Carbene ◽  
New Synthesis

Lutetium and yttrium complexes supported by an anilido-oxazoline ligand for polymerization of 1,3-conjugated dienes and ε-caprolactone

2020 ◽  
Vol 44 (1) ◽  
pp. 121-128
Author(s):  
Wenqiang Li ◽  
Xinxin Jiang ◽  
Yat-Ming So ◽  
Gaohong He ◽  
Yu Pan
Keyword(s):  
High Activity ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Conjugated Dienes ◽  
Conjugated Diene ◽  
Yttrium Complexes

Lutetium and yttrium complexes supported by an anilido-oxazoline ligand exhibit high cis-1,4 stereoselectivity for 1,3-conjugated diene polymerization and high activity for ring-opening polymerization of ε-caprolactone.

scholarly journals Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

2016 ◽  
Vol 12 ◽  
pp. 1949-1980 ◽  
Author(s):  
Lucie Brulíková ◽  
Aidan Harrison ◽  
Marvin J Miller ◽  
Jan Hlaváč
Keyword(s):  
Alder Reaction ◽  
Conjugated Dienes ◽  
Diels Alder ◽  
Conjugated Diene ◽  
Diels Alder Reaction ◽  
Oxazine Ring

The hetero-Diels–Alder reaction between a nitroso dienophile and a conjugated diene to give the 3,6-dihydro-2H-1,2-oxazine scaffold is useful for the synthesis of many biologically interesting molecules due to the diverse opportunities created by subsequent transformations of the resulting 1,2-oxazine ring. This review discusses the rationale for the observed regio- and stereoselectivity and the methods developed in recent years used to control and improve the stereo- and regioselectivity for the synthesis of 1,2-oxazine scaffolds.

scholarly journals The effects of ascorbate and dehydroascorbate on the oxidation of low-density lipoprotein

1996 ◽  
Vol 320 (2) ◽  
pp. 373-381 ◽  
Author(s):  
Suzanne E. STAIT ◽  
David S. LEAKE
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Conjugated Dienes ◽  
Ldl Oxidation ◽  
Lag Phase ◽  
Prolonged Storage ◽  
Low Density ◽  
Dependent Manner ◽  
Conjugated Diene

Ascorbate at concentrations of 60–100 µM inhibits the modification of freshly prepared low-density lipoprotein (LDL) by macrophages. With ‘moderately oxidized’ LDL (produced by prolonged storage in a refrigerator), however, ascorbate does not inhibit LDL modification by macrophages and actually modifies the LDL itself in the absence of macrophages [Stait and Leake (1994) FEBS Lett. 341, 263–267]. We have now shown that dehydroascorbate can modify both ‘fresh’ LDL and moderately oxidized LDL in a dose-dependent manner to increase its uptake by macrophages. The modification of moderately oxidized LDL by ascorbate and dehydroascorbate or of ‘fresh’ LDL by dehydroascorbate is dependent on the presence of iron or copper. In ‘fresh’ LDL, ascorbate inhibited conjugated-diene formation by copper. In moderately oxidized LDL, the number of conjugated dienes present was decreased rapidly in the presence of copper and ascorbate. Dehydroascorbate decreased the lag phase and increased the rate of copper-induced conjugated-diene formation in ‘fresh’ LDL (although in some experiments it inhibited the formation of conjugated dienes). The ascorbate-modified moderately oxidized LDL was taken up by macrophages by their scavenger receptors, as the uptake was inhibited by polyinosinic acid or fucoidan. Ascorbate and dehydroascorbate therefore have the potential to increase LDL oxidation under certain conditions, but whether or not they do so in vivo is unknown.

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