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Letters in Organic Chemistry
ISSN: 1570-1786
Letters in Organic Chemistry
Volume 6, Number 4, June 2009
Contents
Synthesis of Novel Laurenditerpenol Analogues and their Evaluation
as HIF-1 Activation Inhibitors Pp. 269-271
Nikolaos Athinaios, Athanasios Kazantzis,
Kerstin Putzker, Joe Lewis and Emmanuel N. Pitsinos
[Abstract] [Purchase
Article]
Bone Targeting Prodrugs Based on Peptide
Dendrimers, Synthesis and Hydroxyapatite Binding In Vitro
Pp. 272-277
Liang Ouyang, Wencai Huang, Gu He and
Li Guo
[Abstract] [Purchase Article]
Synthesis and Antitumor Evaluation of
Thiophene Analogs of Kigelinone Pp. 278-281
Jaime A. Valderrama, Omar Espinoza, Jaime
Rodriguez and Cristina Theoduloz
[Abstract] [Purchase Article]
Synthesis and Biological Evaluation of
the Pyrazole Class of Cyclooxygenase-2-Inhibitors Pp.
282-288
Samia M. Rida, Manal N.S. Saudi, Amal M.
Youssef and Madiha A. Halim
[Abstract] [Purchase Article]
First Synthesis of Lissoclimide-Type
Alkaloids Pp. 289-292
Miguel A. González, Dámaris
Romero, Bibiana Zapata and Liliana Betancur-Galvis
[Abstract] [Purchase Article]
A Mild and Convenient Synthesis of 4-Tosyl-4,5-dihydrooxazoles
Pp. 293-296
Xavier Companyó, Albert Moyano
and Ramon Rios
[Abstract] [Purchase Article]
Effects of Ionic Liquids for Lipase-Catalyzed
Chiral 1,1`-binaphthyl-2-yl(phenyl)methanone O-acetyl
Oxime Synthesis Pp. 297-300
Yongchang Zhou, Motohiro Takahashi, Naoto
Aoyagi, Chunlei Li, Tatsuro Kijima and Taeko Izumi
[Abstract] [Purchase Article]
A New Organocatalytic Approach to Substituted
Unsaturated Lactams Pp. 301-305
Margherita De Rosa, Carmen Talotta and
Annunziata Soriente
[Abstract] [Purchase Article]
Synthesis and Antibacterial Activities
of (9S)-3-O-descladinose- 6-O-methyl-3-oxo-12-(Δ2-pyrazolinyl)-12-dehydroxy-21-demethyl-9-dihydroerythromycin
A Pp. 306-310
Yong-Tao Wang, Lei Hu, Wei-Min Chen, Ai-Xi
Hu Qiu-Ling Song and Dong Guan
[Abstract] [Purchase Article]
Cyclization of p-tert-Butylcalix[6]arene
with Diols Under the Mitsunobu Protocol. A Conformational
Study of the Peralkylated Derivatives Pp.
311-315
Alajos Grün, Barbara Balázs
and István Bitter
[Abstract] [Purchase Article]
Synthesis of 1,3-Dithiole-2-thione-4,5-dithiolate-Carbohydrate
Conjugate Pp. 316-318
Angelica M. Heinrich, Shahnaz Perveen, Khalid
M. Khan, Gerardo C. Janairo, Gernot Bruchelt, Syed Tasadaque
Ali Shah and Wolfgang Voelter
[Abstract] [Purchase Article]
A Mild and Alternative Approach Towards
Symmetrical Disulfides using H3IO5/NaHSO3
Combination Pp. 319-320
Khalid M. Khan, Muhammad Taha Muhammad Ali
and Shahnaz Perveen
[Abstract] [Purchase Article]
Synthesis and Reactions of the Optically
Active Dialkyl Diselenides from the Pinane Group Pp.
321-328
Zbigniew Rafinski, Jacek Scianowski and
Andrzej Wojtczak
[Abstract] [Purchase Article]
Salan-Vanadium Catalyzed Enantioselective
Desymmetrization of meso-Epoxides with Aromatic Thiols
Pp. 329-331
Jiangtao Sun, Weijin Gu, Yijun Huang, Xu
Pan and Chengjian Zhu
[Abstract] [Purchase Article]
Immobilization of Chiral Quininium Salt
in Ionic Liquid for Enantioselective Epoxidation of Chalcones
Pp. 332-334
Ravindra R. Pal, Ravindra T. Dere, Prashant
S. Patil, Basi V. SubbaReddy and Manikrao M. Salunkhe
[Abstract] [Purchase Article]
Efficient Oxidation of Sulfides to the
Sulfoxides Using Zirconium (IV) Chloride, Sodium Nitrite and
Catalytic Amounts of Bromide Ion as a Novel Oxidizing Media
Pp. 335-339
Arash Ghorbani-Choghamarani, Hamid Goudarziafshar,
Mohsen Nikoorazm and Somaieh Yousefi
[Abstract] [Purchase Article]
Synthesis and Conformational Preferences
of Novel Steroidal 16-Spiro-1,3,2-Dioxaphosphorinanes
Pp. 340-344
Éva Frank, László Sipos,
János Wölfling and Gyula Schneider
[Abstract] [Purchase Article]
Solid-Phase Synthesis of 2-Iodomethyl-2,3-dihydrobenzofurans
Using Recyclable Polymer-Supported Selenium Bromide Pp.
345-348
Shouri Sheng, Minggang Hu, Dan Wu, Mingzhong
Cai and Xian Huang
[Abstract] [Purchase Article]
HCOOH, an Inexpensive, Convenient, and
Practical 13C NMR Solvent
for Strong Polar Amino Acids and their Derivatives Pp.
349-353
Ning Chen and Jiaxi Xu
[Abstract] [Purchase Article]
Abstracts
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[Purchase Article]
Synthesis of Novel Laurenditerpenol Analogues and their Evaluation
as HIF-1 Activation Inhibitors
Nikolaos Athinaios, Athanasios Kazantzis,
Kerstin Putzker, Joe Lewis and Emmanuel N. Pitsinos
Employing a flexible synthetic strategy towards laurenditerpenol,
two analogues featuring the 7-oxabicyclo[2.2.1]heptane ring
system present in the natural product have been prepared and
their ability to inhibit HIF-1 activation has been evaluated.
Their weak activity indicates the importance of the cyclohexenol
part of the prototype.
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Bone Targeting Prodrugs Based on Peptide Dendrimers, Synthesis
and Hydroxyapatite Binding In Vitro
Liang Ouyang, Wencai Huang, Gu He and
Li Guo
Novel bone targeting naproxen prodrugs with poly(aspartic
acid) moieties and with two and three poly(aspartic acid)
sequences peptide dendrimers were synthesized using a conventional
method. The modified naproxen conjugates were incubated with
hydroxyapatite in PBS at physiological conditions over 16h.
The study revealed the hydroxyapatite binding properties of
poly(aspartic acid) and it was found that the peptide dendrimer
prodrugs exhibited a faster initial binding and a greater
total binding. The obtained binding data in vitro indicated
that the peptide dendrimers with poly(aspartic acid) sequences
were useful for the development of new bone targeting molecules
for drug delivery to bone.
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Synthesis and Antitumor Evaluation of Thiophene Analogs of
Kigelinone
Jaime A. Valderrama, Omar Espinoza, Jaime
Rodriguez and Cristina Theoduloz
The synthesis of kigelinone thiophene analogs and related
naphtho[2,3-b]thiophene-4,9-quinones from 2-substituted
4,7-dimethoxybenzo[b]thiophenes via an oxidative
deprotection, Diels-Alder, and oxidative aromatization reaction
sequence is reported. The 2-substituted naphtho[2,3-b]thiophene-4,9-quinones
display significant antitumor activity in the range IC50
1.1-47 μM
on a panel of four distinct human cancer cell lines.
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Synthesis and Biological Evaluation of the Pyrazole Class
of Cyclooxygenase-2-Inhibitors
Samia M. Rida, Manal N.S. Saudi, Amal M.
Youssef and Madiha A. Halim
Several 1,3,4-trisubstituted pyrazole derivatives were
synthesized via condensation with the appropriate
amine, sulphonamide, acid hydrazide, or benzyl thiosemicarbazide
derivatives. The newly synthesized compounds were screened
for a possible anti-inflammatory effect in a rat model of
air-pouch carrageenan-induced inflammation. The results revealed
that some of the newly synthesized compounds exhibited a significant
anti-inflammatory effect in terms of reducing exudation and/or
leukocytic accumulation at the site of inflammation. Thus,
compared to carrageenan-induced inflammation group, compounds
3, 9, 13, and 17 were particularly
associated with significant decrease in both the volume of
exudate and leukocyte accumulation while compounds 4,
7, 10, 11 and 15 were associated
with significant decrease in the volume of inflammatory exudate
without a corresponding decrease in the number of accumulated
leukocytes. Moreover, a docked pose of compound 17
was obtained and bound to cyclooxygenase active site of COX-2
using Molecular Operating Environment (MOE) module.
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First Synthesis of Lissoclimide-Type Alkaloids
Miguel A. González, Dámaris
Romero, Bibiana Zapata and Liliana Betancur-Galvis
The first synthesis of lissoclimide-type alkaloids is
described. Starting from commercial (+)-sclareolide, the aldehyde
γ-bicyclohomofarnesal
is synthesized and coupled, through an aldol reaction, with
succinimide. The antitumor activity of several lissoclimide
analogues is also reported.
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A Mild and Convenient Synthesis of 4-Tosyl-4,5-dihydrooxazoles
Xavier Companyó, Albert Moyano
and Ramon Rios
A facile and mild synthesis of 4-tosyl-4,5-dihydrooxazoles
is described. The reaction between tosyl methyl isocyanide
(TosMIC) and cinnamic or aromatic aldehydes is catalyzed by
triethylamine, affording trans-5-styryl- or 5-aryl-4-tosyl-4,5-dihydrooxazoles
in quantitative yields without further purification. The mild
reaction conditions allowed for the first time the use of
cinnamaldehyde derivatives with excellent results.
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Effects of Ionic Liquids for Lipase-Catalyzed Chiral 1,1`-binaphthyl-2-yl(phenyl)methanone
O-acetyl Oxime Synthesis
Yongchang Zhou, Motohiro Takahashi, Naoto
Aoyagi, Chunlei Li, Tatsuro Kijima and Taeko Izumi
The resolution of 1,1'-binaphthyl-2-yl(phenyl)methanone
O-acetyl oxime catalyzed by lipase in three different ionic
liquids, 1-butyl-3-methylimidazolium hexafluoride-phosphate,
[bmim][PF6], 1-butyl-3-methylimidazolium
tetrafluoroborate, [bmim][BF4]
and N-butyl-pyridium hexafluorophosphate, [BuPy][PF6]
and organic solvents was studied. The lipase shows low activity
in ionic liquids and organic solvent with ionic liquids as
the additive, while the lipase coated with ionic liquids gives
the best enantioselectivity as high as 95 %
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A New Organocatalytic Approach to Substituted Unsaturated
Lactams
Margherita De Rosa, Carmen Talotta and
Annunziata Soriente
The first organocatalytic approach to erythro
and threo lactam derivatives was successfully achieved
from the addition of TBSOP (1) to aromatic
and aliphatic aldehydes in the presence of a commercially
available urea-derivative 5 supporting the
broad potential for hydrogen-bond catalysis in the vinylogous
Mukaiyama aldol addition. The transition states leading to
the major diastereoisomers are discussed.
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Synthesis and Antibacterial Activities of (9S)-3-O-descladinose-
6-O-methyl-3-oxo-12-(Δ2-pyrazolinyl)-12-dehydroxy-21-demethyl-9-dihydroerythromycin
A
Yong-Tao Wang, Lei Hu, Wei-Min Chen, Ai-Xi
Hu Qiu-Ling Song and Dong Guan
A new kind of ketolides, bearing a pyrazolinyl moiety
at C-12 position, was designed and firstly synthesized starting
from clarithromycin via ten steps. The title compound
was evaluated for its antibacterial activities against several
pathogens in vitro, and was found with potent effects
on both S. aureus (ATCC6538p) and S. epidermidis
(ATCC12228). The structures of new compounds were elucidated
by 1HNMR, 13CNMR,
MS and HRMS.
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Cyclization of p-tert-Butylcalix[6]arene with Diols
Under the Mitsunobu Protocol. A Conformational Study of the
Peralkylated Derivatives
Alajos Grün, Barbara Balázs
and István Bitter
p-tert-Butylcalix[6]arene was attempted to O-alkylate
with alcohols and diols under the Mitsunobu protocol. Regio-and
conformation-selective reactions were not observed with alcohols
and oligoethylene glycols, but 1,6-hexane-and 1,8-octanediols
effected cone-selective A,D-bridging. Exhaustive alkylation
of the remaining four OH groups in a cyclized molecule was
carried out under base-promoted conditions and the conformation
of the products along with the metal ion binding properties
were studied by NMR methods.
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Synthesis of 1,3-Dithiole-2-thione-4,5-dithiolate-Carbohydrate
Conjugate
Angelica M. Heinrich, Shahnaz Perveen, Khalid
M. Khan, Gerardo C. Janairo, Gernot Bruchelt, Syed Tasadaque
Ali Shah and Wolfgang Voelter
Bis(tetraethylammonium)bis(1,3-dithiole-2-thione-4,5-dithiolato)
zincate (5), and 4,5-bis(cyanoethylthio)-1,3-dithiole-2-thione
(6) were reacted with 6-deoxy-6-iodo-glucopyranose
(2) and glucopyranosyl bromide (3)
to synthesize DMIT-carbohydrate conjugates.
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A Mild and Alternative Approach Towards Symmetrical Disulfides
using H3IO5/NaHSO3
Combination
Khalid M. Khan, Muhammad Taha Muhammad Ali
and Shahnaz Perveen
Treatment of thiols with a mixture of periodic acid/sodium
hydrogen sulfite gave the corresponding disulfides in good
yield.
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Synthesis and Reactions of the Optically Active Dialkyl Diselenides
from the Pinane Group
Zbigniew Rafinski, Jacek Scianowski and
Andrzej Wojtczak
A convenient method of synthesis of the optically active
dialkyl diselenides from the pinane group is described. The
3-hydroxy and 3-alkoxy derivatives of bis(cis-myrtanyl)
diselenide have been obtained. The influence of a structure
of the resulting diselenides on the diastereomeric excess
of the methoxyselenenylation reaction and the selenocyclization
have been investigated.
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Salan-Vanadium Catalyzed Enantioselective Desymmetrization
of meso-Epoxides with Aromatic Thiols
Jiangtao Sun, Weijin Gu, Yijun Huang, Xu
Pan and Chengjian Zhu
The first example of salan-vanadium catalyzed enantioselective
ring-opening of meso-epoxides has been reported,
which furnished β-hydroxy
sulfides in good yields and moderate enantioselectivities.
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Immobilization of Chiral Quininium Salt in Ionic Liquid for
Enantioselective Epoxidation of Chalcones
Ravindra R. Pal, Ravindra T. Dere, Prashant
S. Patil, Basi V. SubbaReddy and Manikrao M. Salunkhe
An ionic liquid mediated novel protocol for enantioselective
epoxidation of α,β-unsaturated
ketones employing hydrogen peroxide as an oxidant in the presence
of phase transfer catalyst has been developed. The protocol
is essentially mild, rapid and environmentally benign employing
ambient temperature ionic liquids. The use of ionic liquids
facilitates ease of product isolation and catalyst recovery.
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Efficient Oxidation of Sulfides to the Sulfoxides Using Zirconium
(IV) Chloride, Sodium Nitrite and Catalytic Amounts of Bromide
Ion as a Novel Oxidizing Media
Arash Ghorbani-Choghamarani, Hamid Goudarziafshar,
Mohsen Nikoorazm and Somaieh Yousefi
Chemo and homoselective catalytic oxidation of sulfides
has been developed. A variety of aliphatic and aromatic sulfides
are subjected to the sulfoxidation reaction using ZrCl4,
NaNO2 and catalytic amounts
of KBr or NaBr in the presence of wet SiO2
(50 % w/w) in acetonitrile at room temperature.
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Synthesis and Conformational Preferences of Novel Steroidal
16-Spiro-1,3,2-Dioxaphosphorinanes
Éva Frank, László Sipos,
János Wölfling and Gyula Schneider
The diastereomeric pairs a and b
of novel 16-spiro-dioxaphosphorinanes 3–11
were synthesised via the phosphorylation of 16,16-bis(hydroxymethyl)estrone
3-methyl ether (1) and its 17β-hydroxy
analogue (2) and their stereostructures were
investigated by different NMR methods.
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Solid-Phase Synthesis of 2-Iodomethyl-2,3-dihydrobenzofurans
Using Recyclable Polymer-Supported Selenium Bromide
Shouri Sheng, Minggang Hu, Dan Wu, Mingzhong
Cai and Xian Huang
Reaction of polymer-supported selenium bromide with ortho
allylated phenols and subsequent cleavage from the polymer
by treatment of methyl iodide efficiently afforded 2-iodomethyl-2,3-dihydrobenzofurans
in good yields and high purities. The polymeric reagent can
be regenerated and reused as environmentally friendly reagent.
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HCOOH, an Inexpensive, Convenient, and Practical 13C
NMR Solvent for Strong Polar Amino Acids and their Derivatives
Ning Chen and Jiaxi Xu
Amino acids and some of their derivatives are strong
polar organic compounds. Non-deuterated formic acid was used
as an inexpensive, convenient, and practical 13C
NMR solvent for these strong polar compounds. It was also
used to determine hydroxyl carboxylic acids and nucleosides.
13C NMR chemical shifts in
formic acid of representative examples and widely used solvents
in organic reactions were provided. Formic acid is a counterpart
to commonly used perdeuterated chloroform, dimethyl sulfoxide,
methanol, and water.
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