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.

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.

A Novel Entry to the PC-Double Bond: the“Phospha-Wittig” Reaction

1988 ◽  
Vol 27 (10) ◽  
pp. 1382-1384 ◽  
Author(s):  
Angela Marinetti ◽  
François Mathey
Keyword(s):  
Double Bond ◽  
Wittig Reaction

FURTHER EVIDENCE FOR CYCLIC MONOMERS IN HEATED LINSEED OIL

1961 ◽  
Vol 39 (10) ◽  
pp. 1906-1914 ◽  
Author(s):  
A. G. McInnes ◽  
F. P. Cooper ◽  
J. A. MacDonald
Keyword(s):  
Double Bond ◽  
Infrared Spectra ◽  
Chemical Structure ◽  
Linseed Oil ◽  
Carbon Skeleton ◽  
Side Chain ◽  
Partition Chromatography

The distillable esters of heated linseed oil contain a fraction, designated NAFD, which fails to form an adduct with urea. NAFD itself has now been separated into three fractions by gas-liquid partition chromatography. The chemical structure of these component esters was investigated by means of their infrared spectra and by analysis of the products obtained on oxidation of the esters with periodate–permanganate. It is concluded that all the components have the same carbon skeleton, namely, 1-propyl-2-alkenecarboxycyclohexene, but differ in the position of the double bond in the side chain.

RELATIVE RATES OF REACTION OF OZONE WITH OLEFINS IN THE VAPOR PHASE

1960 ◽  
Vol 38 (7) ◽  
pp. 1053-1062 ◽  
Author(s):  
T. Vrbaski ◽  
R. J. Cvetanović
Keyword(s):  
Double Bond ◽  
Carbon Atom ◽  
Vapor Phase ◽  
Reaction Products ◽  
Initial Formation ◽  
Inhibiting Effect ◽  
Π Complex ◽  
Olefinic Double Bond

Relative rates of reaction of ozone with a number of olefins in the vapor phase have been determined by the use of the competitive method and GLC analysis of the reaction products. The results indicate a basic electrophilic trend onto which is superimposed a trend due to a partially inhibiting effect of the substituent groups, in particular of those on the more substituted carbon atom of the olefinic double bond. The results are discussed particularly in terms of a two-step addition process, involving an initial formation of an ozone–olefin π-complex and a slower rearrangement of the π-complex into the cyclic "initial ozonide".

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