Synthesis of some 2,3- and 5,6-unsaturated 19-homosteroids bearing an oxygen containing group at the position 19a

1983 ◽  
Vol 48 (12) ◽  
pp. 3589-3596 ◽  
Author(s):  
Pavel Kočovský
Keyword(s):  
Double Bond ◽  
Methyl Ether ◽  
Hydroxyl Group ◽  
Key Steps

A synthesis of 5,6- and 2,3-unsaturated 19a-methoxy-19a-homocholestane derivatives XVII and XXI is reported. The key steps in the synthesis of the former compound is protecting the 3β-hydroxyl group and 5,6-double bond by conversion to a cyclosteroid (IX → VI, selective hydroboration of the protected steroid followed by methylation (VI → X → XI) and reductive removal of the 3β-substituent (XVI → XVII). The 2,3-unsaturated methyl ether XXI was obtained by elimination from the mesylate XX prepared from the 5,6-unsaturated derivative XV in three steps.

Combinatorial Synthesis of Novel 9R-Acyloxyquinine Derivatives as Insecticidal Agents

2020 ◽  
Vol 23 (2) ◽  
pp. 111-118
Author(s):  
Zhiping Che ◽  
Jinming Yang ◽  
Di Sun ◽  
Yuee Tian ◽  
Shengming Liu ◽  
...  
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Insecticidal Activity ◽  
Structural Modification ◽  
Combinatorial Synthesis ◽  
Hydroxyl Group ◽  
Botanical Insecticide ◽  
Mythimna Separata ◽  
Lead Compounds

Background: It is one of the effective ways for pesticide innovation to develop new insecticides from natural products as lead compounds. Quinine, the main alkaloid in the bark of cinchona tree as well as in plants in the same genus, is recognized as a safe and potent botanical insecticide to many insects. The structural modification of quinine into 9R-acyloxyquinine derivatives is a potential approach for the development of novel insecticides, which showed more toxicity than quinine. However, there are no reports on the insecticidal activity of 9Racyloxyquinine derivatives to control Mythimna separata. Methods: Endeavor to discover biorational natural products-based insecticides, 20 novel 9Racyloxyquinine derivatives were prepared and assessed for their insecticidal activity against M. separata in vivo by the leaf-dipping method at 1 mg/mL. Results: Among all the compounds, especially derivatives 5i, 5k and 5t exhibited the best insecticidal activity with final mortality rates of 50.0%, 57.1%, and 53.6%, respectively. Conclusion: Overall, a free 9-hydroxyl group is not a prerequisite for insecticidal activity and C9- substitution is well tolerated; modification of out-ring double-bond is acceptable, and hydrogenation of double-bond enhances insecticidal activity; Quinine ring is essential and open of it is not acceptable. These preliminary results will pave the way for further modification of quinine in the development of potential new insecticides.

Electrochemical Heterodifunctionalization of α-CF3 Alkenes to Access α-Trifluoromethyl-β-sulfonyl Tertiary Alcohols

2021 ◽  
Author(s):  
Zhi-Peng Ye ◽  
Jie Gao ◽  
Xin-Yu Duan ◽  
Jianping Guan ◽  
Fang Liu ◽  
...  
Keyword(s):  
Double Bond ◽  
Hydroxyl Group ◽  
Tertiary Alcohols ◽  
Olefinic Double Bond

An unprecedented electrochemical heterodifunctionalization of α-CF3 alkenes with benzenesulfonyl hydrazides was accomplished in this work, wherein a β-sulfonyl and a α-hydroxyl group were simultaneously incorporated across the olefinic double bond...

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.

scholarly journals SYNTHESIS, IN VITRO ANTIOXIDANT AND ANTIMICROBIAL EVALUATION OF 3-HYDROXY CHROMONE DERIVATIVES

2018 ◽  
Vol 11 (3) ◽  
pp. 259
Author(s):  
Pallavi Kamble ◽  
Sailesh Wadher
Keyword(s):  
Antioxidant Activity ◽  
Double Bond ◽  
Antifungal Activity ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Antibacterial And Antifungal Activity ◽  
Activity Data ◽  
Group 4 ◽  
Antibacterial And Antifungal

 Objective: The objective of the present study was to synthesize a series of 3-hydroxychromone derivatives and to evaluate its in vitro antioxidant and antimicrobial activities.Methods: 3-hydroxy chromones were synthesized using an algar flynn oyamada method which includes oxidative cyclization of 2-hydroxy chalcones in basic solution by hydrogen peroxide. 2-hydroxy chalcones were synthesized by Claisen-Schmidt condensation of substituted 2-hydroxy acetophenones with substituted aromatic aldehydes using polyethylene glycol-400 as a recyclable solvent. The synthesized compounds were evaluated for in vitro antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. In addition, these compounds were also screened for in vitro antibacterial and antifungal activity by agar cup method and Poison plate method, respectively.Results: The structures of the synthesized compounds were characterized by infrared, 1H nuclear magnetic resonance and mass spectroscopy. The antioxidant activity data revealed that all the synthesized derivatives exhibited good activity due to the presence of phenolic hydroxyl group, 4-oxo group and 2,3-double bond. Further, the activity increased with the introduction of a more phenolic hydroxyl group and adjacent methoxy group in the structure. The antimicrobial activity data showed that the compounds possess better antibacterial and antifungal activity which is attributed to the presence of phenolic hydroxyl group and 4-oxo group in the structure.Conclusions: The use of inexpensive, eco-friendly and readily available reagents, easy work-up and high purity of products makes the procedure a convenient and robust method for the synthesis of title compounds. The presence of phenolic hydroxyl group, 4-oxo group, and 2,3-double bond in the structure is responsible for their good antioxidant and antimicrobial activities.

Exploratory synthetic investigations related to 12a-deoxypillaromycinone

2002 ◽  
Vol 80 (6) ◽  
pp. 728-738 ◽  
Author(s):  
Lan Wang ◽  
Sanath K Meegalla ◽  
Cheng-Lin Fang ◽  
Nicholas Taylor ◽  
Russell Rodrigo
Keyword(s):  
Double Bond ◽  
Catalytic Hydrogenation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Step Procedure ◽  
Key Steps

Furfural is converted to suitably substituted AB synthon 21 for 12a-deoxypillaromycinone in 10 steps by a sequence involving the following key steps: intramolecular Diels-Alder reaction of a furan, 5-endo-trig cleavage of the oxabicyclo adducts 18, and catalytic hydrogenation of the double bond of a tetrasubstituted enone to produce 19. Enones 21a and 21b obtained by dehydrogenation of 19a and 19b, respectively, are then annulated with ethyl 2-methoxy-6-methylbenzoate in a four-step procedure to generate tetracyclic products 25 in 14 steps from furfural.

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.

Hydrogenation of cinnamyl methyl ether and allylbenzene on palladium catalysts

1987 ◽  
Vol 52 (4) ◽  
pp. 1015-1020 ◽  
Author(s):  
Libor Červený ◽  
Ivo Paseka ◽  
Eva Fialová ◽  
Vlastimil Růžička
Keyword(s):  
Double Bond ◽  
Solvent Effect ◽  
Benzene Ring ◽  
Methyl Ether ◽  
Atmospheric Pressure ◽  
Palladium Catalysts ◽  
Polar Medium ◽  
Adsorbed Molecules ◽  
Ionic Nature ◽  
Bond Splitting

The hydrogenation of cinnamyl methyl ether and allylbenzene in hexane and acetone at 20 °C and atmospheric pressure of hydrogen has been studied on eight palladium catalysts. The hydrogenation of cinnamyl methyl ether is accompanied by C-O bond splitting giving rise to propylbenzene and methanol, the hydrogenation of allylbenzene is associated with the isomerization of the double bond resulting in its conjugation with the benzene ring. A marked solvent effect on the selectivity of hydrogenation of cinnamyl methyl ether has been observed and ascribed to the effect of solvated protons on the adsorbed molecules of the ether which is promoted by polar medium. The solvent effect on the isomerization of allylbenzene during the hydrogenation is little pronounced, which suggests that this reaction is not of ionic nature.

ALKALOIDS OF LYCOPODIUM ANNOTINUM: PART II. ISOLATION OF FOUR NEW ALKALOIDS

1959 ◽  
Vol 37 (9) ◽  
pp. 1589-1596 ◽  
Author(s):  
F. A. L. Anet ◽  
N. H. Khan
Keyword(s):  
Double Bond ◽  
Countercurrent Distribution ◽  
Hydroxyl Group ◽  
Lycopodium Annotinum ◽  
Acetyl Group

Countercurrent distribution of the alkaloids of Lycopodiumannotinum gave four new bases: annofoline, lycofoline, and α- and β-lofoline. Annofoline, C16H25O2N, contained a keto and a hydroxyl group. Lycofoline, C16H25O2N, possessed at least one hydroxyl group and possibly a double bond, α- and β-Lofoline each had the formula C18H29O3N and contained a hydroxyl and an O-acetyl group.

The synthesis of 5,6-cyclopropanocholestanes with oxygen functions in positions 3 and 7

1986 ◽  
Vol 51 (2) ◽  
pp. 429-435 ◽  
Author(s):  
Ladislav Kohout
Keyword(s):  
Double Bond ◽  
Cyclopropane Ring ◽  
Hydroxyl Group ◽  
Cyclopropane Derivative

The Simmons-Smith methylenation of the double bond in 3β-acetoxycholest-5-en-7-ols takes place selectively under formation of an adduct the configuration of which is determined by the configuration of the 7-hydroxyl group: 7β-alcohol IV gave 5β,6β-cyclopropane derivative VI, 7α-alcohol V gave 5α,6α-cyclopropane derivative VIII. On photochemically initiated cyclization of 3β-acetoxy-B-homo-5-en-7a-one (XIII) we obtained the product with an α-cyclopropane ring exclusively, i.e. 3β-acetoxy-5,6α-cyclopropano-5α-cholestan-7-one (XII).

scholarly journals Synthesis of [1,4]Oxathiepino[5,6-b]quinolines via Base-Mediated Intramolecular Hydroalkoxylation

SynOpen ◽  
2022 ◽  
Vol 06 (01) ◽  
pp. 7-10
Author(s):  
Morteza Shiri ◽  
Maryam-Sadat Tonekaboni ◽  
Zahra Tanbakouchian ◽  
Soma Majedi
Keyword(s):  
Double Bond ◽  
Hydroxyl Group ◽  
High Yield ◽  
Formyl Group ◽  
Bond Yields ◽  
Terminal Double Bond ◽  
Subsequent Addition

AbstractA base-mediated intramolecular hydroalkoxylation that was used to prepare a series of seven-membered S,O-heterocycles is described. 2-Thiopropargyl-3-hydroxymethyl quinolines were prepared starting from 2-mercaptoquinoline-3-carbaldehydes, via S-propargylation and reduction of a formyl group. Interestingly, 2-mercaptopropargyl-3-hydroxymethyl quinolines were converted into the corresponding oxathiepinoquinolines in the presence of t-BuOK. It is proposed that the S-propargyl moiety, in the presence of base, is converted into its allenyl isomer; subsequent addition of a hydroxyl group to the terminal double bond yields the 3-methyl-5H-[1,4]oxathiepino[5,6-b]quinoline in good to high yield. Notably, the procedure is adaptable to the conversion of N-propargyl indole-2-methanol into the corresponding intramolecular hydroalkoxylation product.

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