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.

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.

C-Lactam Derivatives of Oleanolic Acid. Hydrolysis and Further Acylation of Methyl Acetyloleanolate C-Lactam and C-Thiolactam

2014 ◽  
Vol 9 (3) ◽  
pp. 1934578X1400900
Author(s):  
Barbara Bednarczyk–Cwynar ◽  
Lucjusz Zaprutko
Keyword(s):  
Acetic Anhydride ◽  
Acid Hydrolysis ◽  
Oleanolic Acid ◽  
Alkaline Hydrolysis ◽  
Beckmann Rearrangement ◽  
Mass Spectrometric ◽  
Hydroxyl Group ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Derivatives Of

Acetyl methyl oleanolate was transformed into a seven-membered C-lactam derivative (2) using Beckmann rearrangement of the corresponding C-oxime during the last step of the synthesis. The C=O group of the lactam system was transformed into a C=S group by Lavesson's reagent. The resulting acetylthiolactam 3 and initial acetyllactam 2 were subjected to alkaline hydrolysis to obtain lactam 4 and thiolactam 5 with an unsubstituted C-3 hydroxyl group. Subsequently, compounds 4 and 5 were acylated with either succinic or acetic anhydride in pyridine. Various acylating conditions were tested for hydroxythiolactam 5. The structures of the newly obtained compounds were supported by spectral and mass spectrometric data.

scholarly journals Oxepinamide F biosynthesis involves enzymatic d-aminoacyl epimerization, 3H-oxepin formation, and hydroxylation induced double bond migration

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Liujuan Zheng ◽  
Haowen Wang ◽  
Aili Fan ◽  
Shu-Ming Li
Keyword(s):  
Cytochrome P450 ◽  
Double Bond ◽  
Biosynthetic Pathway ◽  
Hydroxyl Group ◽  
Cytochrome P450 Enzyme ◽  
Double Bond Migration ◽  
Feeding Experiments ◽  
Aspergillus Ustus ◽  
P450 Enzyme ◽  
Derivatives Of

Abstract Oxepinamides are derivatives of anthranilyl-containing tripeptides and share an oxepin ring and a fused pyrimidinone moiety. To the best of our knowledge, no studies have been reported on the elucidation of an oxepinamide biosynthetic pathway and conversion of a quinazolinone to a pyrimidinone-fused 1H-oxepin framework by a cytochrome P450 enzyme in fungal natural product biosynthesis. Here we report the isolation of oxepinamide F from Aspergillus ustus and identification of its biosynthetic pathway by gene deletion, heterologous expression, feeding experiments, and enzyme assays. The nonribosomal peptide synthase (NRPS) OpaA assembles the quinazolinone core with d-Phe incorporation. The cytochrome P450 enzyme OpaB catalyzes alone the oxepin ring formation. The flavoenzyme OpaC installs subsequently one hydroxyl group at the oxepin ring, accompanied by double bond migration. The epimerase OpaE changes the d-Phe residue back to l-form, which is essential for the final methylation by OpaF.

BEZIEHUNGEN ZWISCHEN SUBSTITUTION IM RING A UND ABBAU IM STOFFWECHSEL BEI VERWANDTEN DES TESTOSTERONS

1962 ◽  
Vol 41 (4) ◽  
pp. 494-506 ◽  
Author(s):  
H. Langecker
Keyword(s):  
Double Bond ◽  
Ring System ◽  
Keto Group ◽  
Hydroxyl Group ◽  
Methyl Group ◽  
Structural Peculiarities ◽  
Metabolic Degradation ◽  
The Difference ◽  
Testosterone Metabolites ◽  
Derivatives Of

ABSTRACT Judging from the metabolites found in the urine, 1-methyl-androst-1-en-17β-ol-3-one (methenolone) and testosterone are metabolized in a different manner. For further clarification, other derivatives of testosterone with modifications in Ring A were investigated with regard to the oxidation of the 17-hydroxyl group. The production of urinary 17-ketosteroids decreased in the following sequence: testosterone; 1α-methyltestosterone and androstan-17β-ol-3-one; 1β-methyl-androstan-17β-ol-3-one; 2α-methyl-androstan-17β-ol-3-one and androst-1-en-17β-ol-3-one; 1α-methyl-androstan-17β-ol-3-one; 1-methyl-androsta-1,4-dien-17β-ol-3-one; 1,17α-dimethyl-androst-1-en-17β-ol-3-one and 1 -methyl-androst-1 -en-17β-ol-3-one (methenolone). The difference in metabolic degradation is also demonstrated in the fractionation of the urinary ketones. While after the administration of testosterone practically only hydrogenated 17-ketones are observed in the urine, the unchanged compound is still traceable in remarkable quantities after the administration of methenolone, along with minor quantities of the corresponding diketone. Testosterone-metabolites here are absent, whereas they represent the major substances present after the administration of androst-1-en-17β-ol-3-on. Following the administration of 1α-methyltestosterone only hydrogenated 17-ketones are detected which are still partly methylated. The 1-methyl-group and the Δ 1-double-bond seem to be responsible for the inhibition of the oxidation of methenolone in the 17-position. In addition, the hydrogenation of the double-bond and the reduction of the 3-keto-group are inhibited, obviously on account of the same structural peculiarities. The demethylation of methenolone is also inhibited. Any change in the steroid ring system forms a new substrate, thus producing new conditions for the enzymatic attack in the metabolic degradation.

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.

Ozonolysis of Derivatives of Labda-8(17),14-dien-13-ol (Manool) and Their Conversion Into Large Ring Unsaturated Lactones

1988 ◽  
Vol 41 (5) ◽  
pp. 711 ◽  
Author(s):  
PK Grant ◽  
KL Chee ◽  
JS Prasad ◽  
MY Tho
Keyword(s):  
Double Bond ◽  
Good Yield ◽  
Spatial Relationship ◽  
Hydroxyl Group ◽  
Exocyclic Double Bond ◽  
Large Ring ◽  
Unsaturated Lactones ◽  
Derivatives Of

Dehydration of the unstable hydroperoxy ethers (4) and (6) formed on ozonolysis of the manool derivatives (2) and (5) resulted in the formation of the ten- membered unsaturated lactones (11) and (12) in good yield. The results of an investigation into the nature of the hydroxyl group and its spatial relationship to the exocyclic double bond in lactone formation are reported for other manool derivatives.

scholarly journals Refractive dispersion of organic compounds. V-Oxygenated derivatives of cyclohexane the inadequacy of the Ketteler-Helmholtz equation

1934 ◽  
Vol 146 (857) ◽  
pp. 300-312 ◽  
Keyword(s):  
Double Bond ◽  
Preceding Paper ◽  
Hydroxyl Group ◽  
Double Bonds ◽  
Ring Compounds ◽  
Wide Range ◽  
Olefinic Double Bond ◽  
The One ◽  
Conjugated Compounds ◽  
Derivatives Of

In the preceding paper of this series, refractive indices and molecular extinction coefficients over a wide range of wave-lengths were recorded for the two cyclic hydrocarbons cyclohexene and 1:3- cyclohexadiene . These observations completed a study of the refractive dispersions of the series of 6-ring compounds C 6 H 12 , C 6 H 10 , C 6 H 8 , C 6 H 6 ; they also provided a basis for the study of the phenomenon of "optical exaltation," which is exhibited by compounds containing conjugated double bonds, since the last two members of the series belong to this type. Conjugation, however, may be effected, not only between two olefinic double bonds, but also between an olefinic double bond and an oxygenated radical, such as the carboxyl, carbonyl, or hydroxyl group. The present paper, therefore, records the absorption spectra and refractive dispersions of three oxygenated derivated of cyclohexane, namely, cyclohexanol , cyclohexanone , and ethyl hexahydrobenzoate , in the molecules of which each of the preceding groups is exemplified. Dispersion curves are thus now available for typical compounds of the cyclohexane series containing "unsaturated" radicals of all the principal types which are used in constructing conjugated systems, and the way has been prepared for a detailed study of conjugation, as exemplified on the one hand by cyclo hexadiene, and similar compounds containing two olefinic radicals, and on the other hand by a variety of compounds containing a double bond in addition to a hydroxyl, carbonyl, or carboxyl group. It is anticipated that, with the help of the date set out in the preceding and present papers, it will be possible in a later communication to demonstrate in what respect the behaviour of conjugated compounds differs from that which might be anticipated from a merely additive behaviour of the chromophoric radicals, and thus to determine the nature, and if possible to discover the origin, of the phenomenon of optical exaltation.

TERPENOIDS: X. PRE-SENEGENIN, A QUITE NORMAL TRITERPENOID

1965 ◽  
Vol 43 (7) ◽  
pp. 2033-2046 ◽  
Author(s):  
J. J. Dugan ◽  
P. de Mayo
Keyword(s):  
Double Bond ◽  
Carbon Atom ◽  
Hydrochloric Acid ◽  
Oleanolic Acid ◽  
Empirical Formula ◽  
Carboxyl Group ◽  
Hydrolytic Cleavage ◽  
Group A

Pre-senegenin has been obtained by a combination of oxidative and hydrolytic cleavage of the saponin, and has been shown to be a member of the normal and unrearranged oleanolic acid series: 2β,27-dihydroxy-23-carboxyoleanolic acid (XXII). On treatment with ethanolic hydrochloric acid it is converted quantitatively to a mixture of polygalic acid (XXI) and senegenin.Previous work (1) has shown that senegenin is a triterpenoid of empirical formula C30H45O6Cl with a 2β,3β-glycol system and a 4α-carboxyl group. A second carboxyl group is also present. It has now been found to be a member of the β-amyrin-oleanolic acid series in which a carbon atom at C14 has migrated to C12 with concomitant movement of the double bond to the C13—C14 position, and that it has the structure (XX).

Cyanoacetylenic alcohols, molecules of interstellar origin in the biomimetic synthesis of life relevant heterocycles, amino acids, nucleobases and nucleosides: towards prebiotic chemistry

Synthesis ◽  
2021 ◽  
Author(s):  
Boris Trofimov ◽  
Anastasiya Mal’kina
Keyword(s):  
Amino Acids ◽  
Organic Synthesis ◽  
Prebiotic Chemistry ◽  
Aqueous Media ◽  
Biomimetic Synthesis ◽  
Hydroxyl Group ◽  
Chemical Transformations ◽  
Molecular Architecture ◽  
The Past ◽  
Derivatives Of

Cyanoacetylenic alcohols, R1R2C(OH)C≡C-CN, the closest derivatives of cyanoacetylene, an interstellar abundant molecule, are now becoming acknowledgeable in modern organic synthesis which tends to mimic nature. Highly reactive C≡C and C≡N bonds in close vicinity of the hydroxyl group makes these molecules a chemical trinity of mutually influencing functions ensuring an endless number of chemical transformations. All reactions of cyanoacetylenic alcohols parallel modern organic synthesis, being biomimetic. They do not need transition metals (and in most cases, the metals at all except for physiologically indispensible Na+, K+), proceed at ambient temperature and often in aqueous media. Fundamentally, these reactions are 100% atom-economic because they are almost exclusively addition processes. Usually, in the cyanoacetylenic alcohols, cyano, acetylene and hydroxyl functions behave as inseparable entity providing the multiple functionalizations of the forming molecules. This allows hydroxyl, carbonyl, carboxylic, imino, amino, amido, cyanoamido, cyano, various P-containing, ether and ester functions, along with the double bonds and different fundamental heterocycles (furans, furanones, pyrazoles, oxazoles, pyridines, pyrimidines, purins, etc.) and diverse polycyclic systems to be integrated in a one molecular architecture. This review focuses on analysis and generalization of the knowledge accumulated in the chemistry of these cyanoacetylenic alcohols, mostly over the past 15 years.

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