Glycosylation with ulosonates under Mitsunobu conditions: scope and limitations

2020 ◽  
Vol 44 (34) ◽  
pp. 14463-14476
Author(s):  
Nándor Kánya ◽  
Sándor Kun ◽  
Gyula Batta ◽  
László Somsák
Keyword(s):  
Hydroxy Groups ◽  
Mitsunobu Reactions

Mitsunobu reactions on highly hindered tertiary type hydroxy groups of ulosonates: from 47 NuH compounds O-, N-, and S-nucleophiles gave the corresponding ulosidonates in 30–78% yields, while C-nucleophiles were unreactive.

Determination of Hydroxy Groups in the Modified Epoxy Oligomers Using IR-Spectroscopy

2015 ◽  
Vol 9 (4) ◽  
pp. 411-416 ◽  
Author(s):  
Ostap Ivashkiv ◽  
◽  
Piotr Bruzdziak ◽  
Olena Shyshchak ◽  
Jacek Namiesnik ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Epoxy Oligomers ◽  
Hydroxy Groups ◽  
Modified Epoxy

Synthesis of the C19–C30 Bis-THF Fragment of Iriomoteolide-13a via Stepwise SN2 Cyclization and Intramolecular syn-Oxypalladation

2020 ◽  
Author(s):  
Hui Zhao ◽  
Kai Gao ◽  
Haichen Ma ◽  
Tsz Chun Yip ◽  
Wei-Min Dai
Keyword(s):  
Aldol Reaction ◽  
Allylic Alcohol ◽  
Asymmetric Dihydroxylation ◽  
Hydroxy Groups

The C19–C30 bis-THF fragment of the proposed structure of iriomoteolide-13a has been synthesized. The w-mesyloxy-substituted stereotetrad possessing three continuous hydroxy groups was generated by <i>anti</i>-aldol reaction and asymmetric dihydroxylation (AD). Upon heating in pyridine the stereotetrad underwent an S<sub>N</sub>2 cyclization to form the C19–C22 THF ring. It was followed by an intramolecular <i>syn</i>-oxypalladation of the C28 chiral allylic alcohol to give the C23–C26 THF ring.

Participation of the oxygen-containing substituent in alkaline saponification of 3,4a-disubstituted 4,4-dimethyl-5,6β-epoxy-A-homo-5β-cholestane derivatives

1986 ◽  
Vol 51 (4) ◽  
pp. 930-936 ◽  
Author(s):  
Helena Velgová
Keyword(s):  
Hydroxy Group ◽  
Acetoxy Group ◽  
Epoxide Ring ◽  
Main Component ◽  
Hydroxy Groups

Alkaline saponification of the 3-acetoxy group in 3,4a-disubstituted 4,4-dimethyl-5,6β-epoxy-A-homo-5βcholestane derivatives I-VI was studied. It was found that the 3α- and 4aα-hydroxy groups participated in the cleavage of the 5β,6β-epoxide ring in the derivatives II-IV: the 5(O)n participation by the 3α-hydroxy group (the derivatives III and IV) led to formation of the transannular 3α,5α-epoxides XII and XIV whereas the participation by the 4aα-hydroxy group (the derivatives II and IV) gave rise to the 4aα,5α-epoxides IX and XV. The 5(O)n participation by the 3α-hydroxy group predominated over the preparation by the 4aα-hydroxy group. In the case of the 4a-keto epoxides V and VI the retroaldol-aldol type isomerization led to formation of 3β-hydroxy-4,4-dimethyl-5,6β-epoxy-A-homo-5β-cholestan-4a-one as the main component of the equilibration mixtures.

scholarly journals Structural Insights into the Interactions of Digoxin and Na+/K+-ATPase and Other Targets for the Inhibition of Cancer Cell Proliferation

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3672
Author(s):  
Yulin Ren ◽  
Sijin Wu ◽  
Joanna E. Burdette ◽  
Xiaolin Cheng ◽  
A. Douglas Kinghorn
Keyword(s):  
Cancer Cell ◽  
Cardiac Glycoside ◽  
Antitumor Agents ◽  
Docking Studies ◽  
Cancer Cell Proliferation ◽  
Antitumor Potential ◽  
Hydroxy Groups ◽  
Structural Insights ◽  
Side Pocket ◽  
Potential Use

Digoxin is a cardiac glycoside long used to treat congestive heart failure and found recently to show antitumor potential. The hydroxy groups connected at the C-12, C-14, and C-3′a positions; the C-17 unsaturated lactone unit; the conformation of the steroid core; and the C-3 saccharide moiety have been demonstrated as being important for digoxin’s cytotoxicity and interactions with Na+/K+-ATPase. The docking profiles for digoxin and several derivatives and Na+/K+-ATPase were investigated; an additional small Asn130 side pocket was revealed, which could be useful in the design of novel digoxin-like antitumor agents. In addition, the docking scores for digoxin and its derivatives were found to correlate with their cytotoxicity, indicating a potential use of these values in the prediction of the cancer cell cytotoxicity of other cardiac glycosides. Moreover, in these docking studies, digoxin was found to bind to FIH-1 and NF-κB but not HDAC, IAP, and PI3K, suggesting that this cardiac glycoside directly targets FIH-1, Na+/K+-ATPase, and NF-κB to mediate its antitumor potential. Differentially, digoxigenin, the aglycon of digoxin, binds to HDAC and PI3K, but not FIH-1, IAP, Na+/K+-ATPase, and NF-κB, indicating that this compound may target tumor autophagy and metabolism to mediate its antitumor propensity.

Preparation and Properties of Phosphate Surfactants Containing Ether and Hydroxy Groups

2009 ◽  
Vol 13 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Shuichi Osanai ◽  
Go Yamada ◽  
Ruri Hidano ◽  
Koji Beppu ◽  
Kimiyoshi Namiwa
Keyword(s):  
Hydroxy Groups

Synthesis of diaminodideoxyalditol analogs of cisplatin as antitumor agents

1993 ◽  
Vol 71 (6) ◽  
pp. 880-885 ◽  
Author(s):  
S. Hanessian ◽  
J.-Y. Gauthier ◽  
K. Okamoto ◽  
A.L. Beauchamp ◽  
T. Theophanides
Keyword(s):  
Antitumor Activity ◽  
Antitumor Agents ◽  
Platinum Complexes ◽  
Hydroxy Groups

Acyclic vicinal polyol complexes related to cisplatin were synthesized from D-mannitol by stereocontrolled manipulation of the hydroxy groups. Controlled cleavage of a 3,4-diazido hexitol gave the corresponding D-threitol and D-xylitol analogs, which were converted to their diamino platinum complexes. The antitumor activity of these compounds is reported.

Candida antarctica lipase B-catalyzed regioselective deacylation of dihydroxybenzenes acylated at both phenolic hydroxy groups

2016 ◽  
Vol 94 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Toshifumi Miyazawa ◽  
Manabu Hamada ◽  
Ryohei Morimoto
Keyword(s):  
Candida Antarctica ◽  
Candida Antarctica Lipase B ◽  
Candida Antarctica Lipase ◽  
Primary Alcohols ◽  
Lipase B ◽  
Highly Active ◽  
Direct Acylation ◽  
Acyl Acceptors ◽  
Hydroxy Groups ◽  
Phenolic Hydroxy

Candida antarctica lipase B proved to be highly active in the deacylation of substituted hydroquinones and resorcinols acylated at both phenolic hydroxy groups. The deacylation reactions were much faster than the corresponding direct acylations of these dihydroxybenzenes catalyzed by the same lipase. More importantly, they took place generally in a markedly regioselective manner: the acyloxy group remote from the substituent was preferentially cleaved. The main or exclusive products obtained were the regioisomers of those produced through the direct acylation of the dihydroxybenzenes. In the case of alkyl-substituted hydroquinone derivatives, the regioselectivity increased with an increase in the bulk of the substituent. In the case of 4-substituted diacylated resorcinols, the 3-O-monoacyl derivatives were obtained generally as the sole products. Quite interestingly, some secondary alcohols proved to act as better acyl acceptors than the corresponding primary alcohols in these enzymatic deacylations.

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