Intramolecular Cyclization of Phenol Derivatives with C=C Double Bond in a Side Chain.

ChemInform ◽  
2007 ◽  
Vol 38 (20) ◽  
Author(s):  
Yoshihiko Ito ◽  
Risa Kato ◽  
Kentaro Hamashima ◽  
Yohei Kataoka ◽  
Yohei Oe ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Side Chain ◽  
Phenol Derivatives

Intramolecular cyclization of phenol derivatives with CC double bond in a side chain

2007 ◽  
Vol 692 (1-3) ◽  
pp. 691-697 ◽  
Author(s):  
Yoshihiko Ito ◽  
Risa Kato ◽  
Kentaro Hamashima ◽  
Yohei Kataoka ◽  
Yohei Oe ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Side Chain ◽  
Phenol Derivatives

A Novel Scheme for the Synthesis of 21-Acetoxypregna-1,4,9(11)-triene- 17α,21-diol-3,20-dione from 9α-Hydroxyandrostenedione

2020 ◽  
Vol 16 (5) ◽  
pp. 606-610
Author(s):  
Nguyen T. Diep ◽  
Luu D. Huy
Keyword(s):  
Double Bond ◽  
Chemical Synthesis ◽  
Economic Efficiency ◽  
Final Stage ◽  
Side Chain ◽  
Entire Process ◽  
Drug Synthesis ◽  
First Time

Background: Vietnam currently imports up to 90% of the pharmaceuticals it consumes and 100% of the steroid-based pharmaceuticals. The ability for efficient chemical synthesis of the steroids could create commercial opportunities to address this issue. Synthesis of 21-acetoxypregna-1,4,9(11)- triene-17α,21-diol-3,20-dione is considered a key intermediate in the scheme of steroidal drug synthesis. Previous synthesis attempts of such steroids (corticoids) introduce a double bond at C-1(2) in the final stage of synthesis, which delivers a poor yield and reduces the economic efficiency of the process. Objective: To study and develop a novel and effective method for the synthesis of 21-acetoxypregna- 1,4,9(11)-triene-17α,21-diol-3,20-dione. Methods: Using 9α-hydroxyandrostenedione as a substrate chemical synthesis was performed as follows: pregnane side chain construction at C-17 (acetylene method), introduction of C-1(2) double bond (using SeO2), epimerization of C-17 (via 17-ONO2 ester) and Stork’s iodination. Results: 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione was prepared from 9α- hydroxyandrostenedione with an improved yield compared to previous attempts. Conclusion: Here, 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione has been synthesized from 9α-hydroxyandrostenedione based on a novel, effective and commercially feasible scheme. The introduction of the C-1(2) double bond at an earlier stage of the synthesis has increased the economic efficiency of the entire process. For the first time, the indirect epimerization mechanism has been clarified along with the configuration of the C-17 stereo-center which has been confirmed using NOESY data.

Critical Review of Biotransformational Studies on Steroids by Using Culture of Cunninghamella blakesleeana

2021 ◽  
Vol 18 ◽  
Author(s):  
Azizuddin ◽  
Muhammad Iqbal ◽  
Syed Ghulam Musharraf
Keyword(s):  
Double Bond ◽  
Critical Review ◽  
Structural Modification ◽  
Bond Formation ◽  
Environmentally Friendly ◽  
Side Chain ◽  
Synthetic Compounds ◽  
Efficient Approach ◽  
Cunninghamella Blakesleeana ◽  
Different Strains

: For several decades, biotransformational studies on steroidal compounds have gained a lot of attention because it is an efficient approach for the structural modification of complicated natural or synthetic compounds with high regio-, chemo- and stereoselectivity at environmentally friendly conditions. This review summarizes the use of different strains of Cunninghamella blakesleeana for the biotransformation of sixteen steroids 1-16 into a variety of transformed products. The transformed products may be important as a drug or precursor for the production of important pharmaceuticals. The types of reactions performed by C. blakesleeana include hydroxylation, epoxidation, reduction, demethylation, oxidation, glycosidation, double bond formation, side-chain degradation, isomerisation and opening of an isoxazol ring, which would be difficult to produce by traditional synthesis.

Migration of the Double Bond in the Side Chain of Sterols with Iodine.

1970 ◽  
Vol 35 (12) ◽  
pp. 4145-4148 ◽  
Author(s):  
Nobuo Ikekawa ◽  
Yasushi Honma ◽  
Naoko Morisaki ◽  
Kiyoshi Sakai
Keyword(s):  
Double Bond ◽  
Side Chain

Extractives of Australian timbers. X. Autoxidation and other reactions of the conjugated side-chain of eberlin lactone. Isolation of a new isomer of ebelin lactone

1970 ◽  
Vol 23 (10) ◽  
pp. 2085 ◽  
Author(s):  
RA Eade ◽  
J Ellis ◽  
JS Shannon ◽  
HV Simes ◽  
JJH Simes
Keyword(s):  
Double Bond ◽  
Solid State ◽  
Osmium Tetroxide ◽  
Side Chain ◽  
Methyl Groups ◽  
Stepwise Manner ◽  
Terminal Double Bond ◽  
Conjugated Triene

The conjugated triene side-chain of ebelin lactone has been degraded in a stepwise manner using osmium tetroxide. A new isomer of ebelin lactone has been isolated from the sapogenin mixture and has been assigned the structure (9) in which the 25(26) double bond has the cis configuration. Autoxidation of ebelin lactone in the solid state yields a mixture from which three compounds have been isolated and identified; all three arise from oxidation of the side-chain at the terminal double bond and methyl groups.

scholarly journals Triterpene Glycosides from the Sea Cucumber Eupentacta Fraudatrix. Structure and Biological Action of Cucumariosides I1, I3, I4, Three New Minor Disulfated Pentaosides

2013 ◽  
Vol 8 (8) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Alexandra S. Silchenko ◽  
Anatoly I. Kalinovsky ◽  
Sergey A. Avilov ◽  
Pelageya V. Andryjaschenko ◽  
Pavel S. Dmitrenok ◽  
...  
Keyword(s):  
Double Bond ◽  
Sea Cucumber ◽  
2D Nmr ◽  
Triterpene Glycosides ◽  
Side Chain ◽  
Ehrlich Carcinoma ◽  
Cytotoxic Activities ◽  
Moderate Activity ◽  
2D Nmr Spectroscopy ◽  
Eupentacta Fraudatrix

Three new minor triterpene glycosides, cucumariosides I1 (1), I3 (2) and I4 (3) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1–3 belong to the group of cucumariosides I, having branched pentasaccharide carbohydrate moieties with two sulfate groups and possessing 3- O-methyl-D-xylose as a terminal monosaccharide unit that is a characteristic feature of all the glycosides isolated from E. fraudatrix. Glycosides 1 and 2 differ from each other by the side chain structures in the holostane aglycone moieties, while cucumarioside I4 (3) has a 23,24,25,26,27-pentanorlanostane aglycone with an 18(16)-lactone. Cytotoxic activities of glycosides 1–3 against mouse spleen lymphocytes and ascite form of mouse Ehrlich carcinoma cells, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Glycoside 1, having an aglycone side chain with a 24(25)-double bond, possesses moderate activity in all the tests, while glycoside 2, having 23(24)-double bond and 25-hydroxy group in the side chain, and glycoside 3 with an aglycone with an 18(16)-lactone and shortened side chain have either low activity or are non-active.

The Synthesis of Diepoxide Analogues of Fumagillin

1979 ◽  
Vol 32 (11) ◽  
pp. 2473 ◽  
Author(s):  
WE Harvey ◽  
JO Miners
Keyword(s):  
Double Bond ◽  
General Type ◽  
Wittig Reaction ◽  
Cyclic Ketone ◽  
Side Chain ◽  
Initial Formation

Pathways from cyclohexanone to compounds of the general type 4-(1',2'-epoxy-1'-methylalkyl)- 1-oxaspiro[2,5]octane (5), the simplest diepoxide analogues of the antibiotic fumagillin (1a), are described. The sequence involves the initial formation of 6-acetyl-1,4-dioxaspiro[4,5]decane (2a) which is converted into a 2-alkenylcyclohexanone through the Wittig reaction. Subsequent spiro epoxidation of the cyclic ketone and peracid epoxidation of the side chain double bond affords the diepoxides (5a-c). In most respects the synthetic diepoxides possess the same stereochemistry as the equivalent functionality of fumagillin.

scholarly journals Intramolecular Cyclization of Ruthenium Vinylidene Complexes with a Tethering Vinyl Group:  Facile Cleavage and Reconstruction of the C−C Double Bond

2007 ◽  
Vol 129 (48) ◽  
pp. 14974-14980 ◽  
Author(s):  
Cheng ◽  
Yi-Chun Kuo ◽  
Shu-Hao Chang ◽  
Ying-Chih Lin ◽  
Yi-Hong Liu ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Vinylidene Complexes ◽  
Vinyl Group
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