The constituents of Cryptocarya pleurosperma White & Francis. I. Pleurospermine: A new alkaloid of the leaves

1959 ◽  
Vol 12 (1) ◽  
pp. 90 ◽  
Author(s):  
E Gellert
Keyword(s):  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Hydroxyl Group ◽  
Veratric Acid ◽  
The Third ◽  
Tertiary Nitrogen Atom ◽  
Group A ◽  
Francis I ◽  
Alcoholic Hydroxyl ◽  
Tertiary Nitrogen

A new alkaloid pleurospermine, C14Hl9O3N, has been isolated from the leaves of Cryptocarya pleurosperma. Pleurospermine contains a methoxyl group, a phenolic hydroxyl group, and a tertiary nitrogen atom. The third oxygen atom is possibly present as an alcoholic hydroxyl group. On heating with palladium-charcoal the alkaloid yields 4-hydroxy-3-methoxyacetophenone (I), while methylation followed by oxidation gives veratric acid.

LYCOPODIUM ALKALOIDS: XVI. ANNOTINE

1964 ◽  
Vol 42 (11) ◽  
pp. 2584-2594 ◽  
Author(s):  
W. A. Szarek ◽  
K. A. H. Adams ◽  
M. Curcumelli-Rodostamo ◽  
D. B. MacLean
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Hydroxyl Group ◽  
Tertiary Nitrogen Atom ◽  
Chemical Studies ◽  
Group A ◽  
Instrumental Methods ◽  
Tertiary Hydroxyl ◽  
Plausible Structure ◽  
Tertiary Nitrogen

Annotine, C16H21O3N, is shown to be pentacyclic and to contain a tertiary hydroxyl group, a lactone function, a tertiary nitrogen atom, and a dialkylated double bond. The position of the double bond and the tertiary hydroxyl group relative to the nitrogen atom has been established by Emde degradation of annotine methiodide. The presence of a lactone function is inferred from the reduction of annotine to dihydroannotinol, a hemiacetal, which reacts with 1 mole of ethyl mercaptan. The reduction of the lactone to a diol in an annotine derivative has been carried out. The chemical studies and the examination of annotine and its derivatives by modern instrumental methods allow the assignment of a plausible structure to the alkaloid.

scholarly journals Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

2021 ◽  
Author(s):  
Dan Sakai ◽  
mizuki machida ◽  
Keiji Mori
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Stereoselective Synthesis ◽  
Hydroxyl Group ◽  
Target Structure ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

scholarly journals Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

2021 ◽  
Author(s):  
Dan Sakai ◽  
mizuki machida ◽  
Keiji Mori
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Stereoselective Synthesis ◽  
Hydroxyl Group ◽  
Target Structure ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

The Alkaloids of Kopsia longiflora Merrill. I. Isolation of the Alkaloids

1955 ◽  
Vol 8 (1) ◽  
pp. 129 ◽  
Author(s):  
WD Crow ◽  
M Michael
Keyword(s):  
Nitrogen Atom ◽  
Rain Forest ◽  
Forest Tree ◽  
Triterpene Alcohol ◽  
Carbonyl Groups ◽  
Alcohol Acetate ◽  
Ultraviolet Spectra ◽  
Tertiary Nitrogen Atom ◽  
Neutral Media ◽  
Tertiary Nitrogen

The bark and leaves of the rain-forest tree Kopsia longiflora Merrill (Apocynaceae) contain four new alkaloids ; kopsinine, C21H26O2N2, (0.2 per cent.), kopsilongine, C24H30O6N2 (0.06 per cent.), and kopsamine, C25H30O7N2 (0.02 per cent.) occurring in the bark ; and kopsilongine (0.07 per cent.), kopsamine (0.3 per cent.), and kopsiflorine, C23H28O5N2, (0.04 per cent.) in the leaves. The bark also contains β-amyrin (0.35 per cent.) while the leaves afford a mixture of paraffin hydrocarbons, mainly n-hentri- acontane, β-sitosterol, a sterol, C29H50O2, and a triterpene alcohol acetate, C32H52O2. Kopsamine, kopsilongine, and kopsiflorine each contain two methoxyl groups, while kopsinine contains only one ; kopsamine and kopsilongine also contain methylene-dioxy-groups. No reactive carbonyl groups were detected. The alkaloids all titrated as monoacid bases and formed monomethiodides: while the ultraviolet spectra recorded in acid and neutral media show that the basic (tertiary) nitrogen atom does not contribute to the chromophoric system.

The use of 7-(2-bromoethoxy)coumarin for the quantitative fluorometric analysis of drug preparations containing a tertiary nitrogen atom

1985 ◽  
Vol 19 (6) ◽  
pp. 430-434
Author(s):  
A. Z. Abyshev ◽  
V. G. Klimov ◽  
S. S. Krylov ◽  
E. V. Semenov ◽  
I. P. Sidorova
Keyword(s):  
Nitrogen Atom ◽  
Tertiary Nitrogen Atom ◽  
Fluorometric Analysis ◽  
Tertiary Nitrogen

scholarly journals C-Lactam Derivatives of Oleanolic Acid. The Synthesis of C-lactam by Beckmann Rearrangement of C-oxime

2011 ◽  
Vol 6 (12) ◽  
pp. 1934578X1100601
Author(s):  
Barbara Bednarczyk – Cwynar
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Oleanolic Acid ◽  
Structure Elucidation ◽  
Beckmann Rearrangement ◽  
Hydroxyl Group ◽  
Chemical Transformations ◽  
Group A ◽  
Derivatives Of ◽  
Carbonyl Function

Oleanolic acid, one of the most known triterpenes, was subjected to different chemical transformations within C-3 β-hydroxyl group, a double bond between C-12 and C-13, and a carboxyl function at C-17 in order to obtain new derivatives. The key compound consists of four six-membered rings (A, B, D, E) and one enlarged ring (C ring) containing a nitrogen atom and a carbonyl function – lactam. This type of derivative can be obtained by Beckmann rearrangement of the appropriate oxime. The lactam can be transformed into thiolactam with the use of Lavesson's reagent. The method is also presented for new derivatives synthesis, as well as their structure elucidation by spectroscopic means.

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