ATISINE: THE HETEROCYCLIC RING AND FUNCTIONAL GROUPS

1954 ◽  
Vol 32 (5) ◽  
pp. 465-473 ◽  
Author(s):  
O. E. Edwards ◽  
Tara Singh
Keyword(s):  
Functional Groups ◽  
Heterocyclic Ring ◽  
Double Bonds ◽  
Secondary Hydroxyl ◽  
Exocyclic Methylene ◽  
Methylene Group ◽  
Hydroxyethyl Group

Evidence is presented which confirms the presence in atisine and isoatisine of vinylamine double bonds, an N-(β-hydroxyethyl) group, an exocyclic methylene group, and a secondary hydroxyl in an allylic relation to the latter. The size and substitution of the heterocyclic ring is discussed. The pyrolysis of atisine and isoatisine hydrochlorides to give a C20H29ON base is described.

Analytical Methods in Rubber Chemistry. Part V. Estimation of the Oxygen of Highly Autoöxidized Rubber Contained in Carboxyl, Ester, Carbonyl, Epoxide and Hydroxyl Groups

1942 ◽  
Vol 15 (4) ◽  
pp. 965-977
Author(s):  
F. Hilton
Keyword(s):  
Functional Groups ◽  
Hydroxyl Groups ◽  
Double Bonds ◽  
Primary Products ◽  
Secondary Reactions ◽  
Methylene Groups ◽  
Products Of Reaction ◽  
Methylene Group ◽  
Alcoholic Hydroxyl ◽  
Oxidative Attack

Abstract In the course of a study of the autoöxidation of natural rubber and of low-molecular olefins of allied structure, it has been necessary to ascertain the nature and relative proportions of the functional groups to which the ingoing oxygen may give rise. Up to the present it has been established that the products of autoöxidation reactions are in general highly complex mixtures, and that even such simple olefins as dihydromyrcene and cyclohexene may give rise to molecules which bear a varied assortment of hydroperoxide, alcoholic hydroxyl, epoxide and carbonyl groups. Available evidence further indicates that the primary products of autoöxidation are hydroperoxides, formed by the reaction of oxygen at methylene groups adjacent to double bonds, and that it is the secondary reactions which these hydroperoxides undergo which are responsible, directly or indirectly, for the formation of the other oxygen-containing groups which have been observed. Molecules of rubber hydrocarbon contain, on an average, several thousand methylene groups adjacent to double bonds. Each such methylene group is at least the potential seat of oxidative attack, and it might be anticipated that if the autoöxidation of rubber proceeds in a manner analogous to that of simpler olefins, the products of reaction would be extremely complex and that they might contain any or all of the following functional groups

EHT study of reactivity of methylene group in 1-methyl-1,4-dihydronicotinamide

1980 ◽  
Vol 45 (9) ◽  
pp. 2425-2432
Author(s):  
Jiří Krechl ◽  
Josef Kuthan
Keyword(s):  
Heterocyclic Ring ◽  
Covalent Bonds ◽  
Electronic Mechanism ◽  
Methylene Group ◽  
Plane Form ◽  
Reaction Profile

It has been demonstrated that the EHT method predicts an almost plane form of the heterocyclic ring in 1-methyl-1,4-dihydronicotinamide I (R = CH3) and also reflects satisfactorily character of the covalent bonds in the 4-methylene group. An attempt has been made of calculation of the reaction profile of elimination of the centre 4', and electronic mechanism of its splitting off is discussed.

scholarly journals Relation between Crystal Structures of Precursors and Final Products: Example of Vitamin D Intermediates

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1802
Author(s):  
Monika Wanat ◽  
Maura Malinska ◽  
Andrzej Kutner ◽  
Krzysztof Woźniak
Keyword(s):  
Vitamin D ◽  
Crystal Structures ◽  
Theoretical Calculations ◽  
Geometrical Parameters ◽  
Space Groups ◽  
Vitamin D Analogues ◽  
Vitamin D Analog ◽  
Exocyclic Methylene ◽  
Solid Form ◽  
Methylene Group

In this paper, we proved that the solid-state structure of vitamin D analog is well represented by the structures of its structural fragments. This is important in predicting the biological activity of vitamin D analogs that are not available in the solid form. The previously published crystal structure of advanced vitamin D intermediate provided additional insights into vitamin D properties. A similar analysis based on simple vitamin D intermediate analogues showed that precursors crystallized in the space groups typical for vitamins D; geometrical parameters were related to the corresponding parameters in the vitamin D analogues; and crystal structures of the basic intermediates and their final products contained similar intermolecular interactions, essential for the infinite hydrogen bond motif observed in the vitamin D analogues. The energy of these interactions is related as shown by theoretical calculations, that is, energy frameworks analysis. Moreover, analysis of the hydrogen bonds motifs revealed a relation between these motifs and the absolute configuration of basic intermediates as well as the space orientation of the exocyclic methylene group in the final structures.

Practical Deoxygenation of Oxazole N-Oxides by PCl3/Collidine

Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 414-420
Author(s):  
Valerii Shirinian ◽  
Ilya Lonshakov ◽  
Alexey Zakharov ◽  
Andrey Lvov ◽  
Mikhail Krayushkin
Keyword(s):  
Functional Groups ◽  
Heterocyclic Compounds ◽  
Phosphorus Trichloride ◽  
Double Bonds ◽  
Wide Range

A new chemoselective method for the synthesis of 2-aryl-1,3-oxazoles by deoxygenation of the corresponding N-oxides has been developed. As the deoxygenation reagent, a previously unknown complex of collidine with phosphorus trichloride in a 2:1 ratio has been used. The developed method enabled the preparation of a wide range of 2-aryl-1,3-oxazoles comprising various functional groups in good yields. The advantage of this reagent is its tolerance to nitro, methyl, hydroxyl, formyl, and acetyl groups, and double bonds. Due to chemoselectivity and availability of reagents, the method may be used for deoxygenation of N-oxides of other heterocyclic compounds (thiazole, pyridine, quinoline, etc.).

scholarly journals A REVIEW ON PYRAZOLINE DERIVATIVES AS ANTIMICROBIAL AGENT

2020 ◽  
pp. 15-24
Author(s):  
SARAS KUMAR JAIN ◽  
ROHIT SINGHAL
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agent ◽  
Heterocyclic Compound ◽  
Pharmacological Action ◽  
Heterocyclic Ring ◽  
Ring Structure ◽  
Double Bonds ◽  
Antitumor Properties ◽  
Anti Inflammatory ◽  
Pyrazoline Derivative

At present, there is a lot of research about the pyrazoline heterocyclic compound, its ring structure is being changed and new derivatives are being made, many of which have antimicrobial activity over the derivatives. Pyrazoline is the five-member heterocyclic ring which have two N atoms in nearby position and contains two endocyclic double bonds. Noteworthy consideration has been concentrated on pyrazolines and pyrazoline derivative due to their important pharmacological action. Some replaced pyrazolines have been stated near retain particular important pharmacological actions as antimicrobial, antifungal, antineoplastic, antidepressant, insecticidal, anticonvulsant, anti-inflammatory, antibacterial and antitumor properties.

Reactions of bridging C3 ligands in diiron complexes: Unconventional routes to new functionalized organic frames

2010 ◽  
Vol 82 (7) ◽  
pp. 1555-1568 ◽  
Author(s):  
Valerio Zanotti
Keyword(s):  
Functional Groups ◽  
Nucleophilic Addition ◽  
Metal Center ◽  
Unusual Reaction ◽  
Nucleophilic Attack ◽  
Double Bonds ◽  
Bridging Ligands ◽  
Reaction Patterns

Diiron complexes containing C3 ligands, such as vinyliminium and vinylalkylidene bridging units, display unusual reaction patterns, not observed when the same organic fragments are bound to a single metal center, or not coordinated. Bridging vinyliminium complexes [Fe2{μ-η1:η3-C(NMe2)CH=CR}(μ-CO)(CO)(Cp)2][SO3CF3] undergo nucleophilic addition at the iminium C or at α-C position, which is uncommon since non-coordinated vinyliminium species generally undergo conjugated (Michael type) nucleophilic attack. Likewise, bridging vinyliminium ligands undergo new and unusual transformations consisting of the deprotonation and replacement of the α-CH by a variety of functional groups. These reactions, resulting in the formation of C–C and C–heteroatom single and double bonds, produce new bridging ligands of the type [μ-C(NMe2)C(X)CR) (X = S, O, Se, SPh, CNMe, NNCHCO2Me]. Removal of the vinylalkylidene ligands from the bridging coordination is achieved by a [3 + 2] cycloaddition with alkynes. The reaction leads to the formation of ferrocenes containing one polysubstituted Cp ring, which results from the cycloaddition of the bridging C3 ligand with alkynes. This result suggests a new possible route for the synthesis of polyfunctionalized ferrocenes.

THE STRUCTURE AND STEREOCHEMISTRY OF ATISINE

1964 ◽  
Vol 42 (1) ◽  
pp. 137-149 ◽  
Author(s):  
D. Dvornik ◽  
O. E. Edwards
Keyword(s):  
Long Range ◽  
Rigorous Proof ◽  
Polar Groups ◽  
Detailed Explanation ◽  
Exocyclic Methylene ◽  
Derivatives Of ◽  
Methylene Group ◽  
Absolute Stereochemistry ◽  
Basic Strength

A stereospecific hydration of the exocyclic methylene group of a derivative of the alkaloid atisine has been observed. The product was used to degrade the alkaloid to a tetracyclic phenol. This enabled rigorous proof of the structure and relative and absolute stereochemistry of atisine and related alkaloids. A detailed explanation of the abnormal basic strength and the isomerization of atisine is given. Long-range influence of polar groups on the basic strength of derivatives of the alkaloid is reported.

Relative reactivities of double bonds in compounds with functional groups towards the dimethylcyanomethyl radical

1989 ◽  
Vol 38 (4) ◽  
pp. 789-792 ◽  
Author(s):  
I. N. Markevich ◽  
G. S. Borisova ◽  
N. N. Glebova ◽  
O. K. Sharaev ◽  
I. Ya. Ostrovskaya ◽  
...  
Keyword(s):  
Functional Groups ◽  
Double Bonds
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