Intramolecular [2 + 2]photocycloadditions of 1-(.omega.-alkenyl)-2-pyridones possessing an ester group on the olefinic carbon chain

1992 ◽  
Vol 57 (21) ◽  
pp. 5708-5712 ◽  
Author(s):  
Kenichi Somekawa ◽  
Hiroyuki Okuhira ◽  
Masayuki Sendayama ◽  
Takaaki Suishu ◽  
Tetsuro Shimo
Keyword(s):  
Ester Group ◽  
Carbon Chain ◽  
Olefinic Carbon

ChemInform Abstract: Intramolecular (2 + 2)Photocycloadditions of 1-(ω-Alkenyl)-2- pyridones Possessing an Ester Group on the Olefinic Carbon Chain.

ChemInform ◽  
2010 ◽  
Vol 24 (7) ◽  
pp. no-no
Author(s):  
K. SOMEKAWA ◽  
H. OKUHIRA ◽  
M. SENDAYAMA ◽  
T. SUISHU ◽  
T. SHIMO
Keyword(s):  
Ester Group ◽  
Carbon Chain ◽  
Olefinic Carbon

Evaluation of Biodegradability of Amine Collectors

2010 ◽  
Vol 113-116 ◽  
pp. 267-271 ◽  
Author(s):  
Heng Zhen Yan ◽  
Wen Qi Gong ◽  
Guang Jun Mei ◽  
Xiao Ye Liu ◽  
Shao Hua Chen
Keyword(s):  
Chemical Structure ◽  
Ester Group ◽  
Carbon Chain ◽  
Ammonium Bromide ◽  
Evaluation Standards ◽  
Testing Method

Amine collectors are widely used as oxidized ore collectors.Based on OECD 301B testing method, the biodegradability of amine collectors were analyzed and evaluated, and the values of IB of lauryl amine, octadecylamine, laurtrimonium chloride, lauryl trimethyl ammonium bromide, decane-propyl ether amine and dodecyl propyl ether amine were 173.4, 162.2, 164.6, 171.2, 160.8 and 149.4, respectively. The biodegradation of six test substances all exceeded 10% in 10 days, and all up to over 50% within 28 days. Considering comprehensively the two evaluation standards, the six amine collectors are all biodegradable. Evaluation of the biodegradability of amine collectors provides information that the chemical structure influences the biodegradability of amine collectors. It seems that the existence of ester group decreases the biodegradability of ether amine, and the shorter the carbon chain, the greater the biodegradation occurred.

Synthesis of carbocycles from ω-substituted α,β-unsaturated esters via radical-induced cyclizations

1987 ◽  
Vol 65 (8) ◽  
pp. 1859-1866 ◽  
Author(s):  
Stephen Hanessian ◽  
Daljit S. Dhanoa ◽  
Pierre L. Beaulieu
Keyword(s):  
Ester Group ◽  
Carbon Chain ◽  
Radical Cyclization ◽  
Unsaturated Esters ◽  
Carbocyclic Compounds ◽  
Bicyclic Structure

The intramolecular radical cyclization of ω-bromo α,β-unsaturated esters for the synthesis of carbocyclic compounds is described. The effect of carbon chain substituents, the bulk of the ester group, and the olefin geometry were examined. The highest level of stereoselectivity (trans/cis: 9/1) was achieved with the Z ester via an exo cyclization. The sequential radical cyclization of a dihalodienoate to give a cis-fused bicyclic structure is also described.

scholarly journals Platinum Complexes with Edda (Ethylenediamine -N, N - Diacetate) Ligands as Potential Anticancer Agents

2016 ◽  
Vol 17 (4) ◽  
pp. 285-296 ◽  
Author(s):  
Milena Jurisevic ◽  
Gordana Radosavljevic ◽  
Aleksandar Arsenijevic ◽  
Marija Milovanovic ◽  
Nevena Gajovic ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Cisplatin Resistance ◽  
Platinum Complexes ◽  
Ester Group ◽  
Carbon Chain ◽  
Platinum Compound ◽  
Necrotic Cell ◽  
High Level ◽  
Group Carbon ◽  
Ester Chain

Abstract The design of platinum based drugs is not a new field of interest. Platinum complexes are widely used as anticancer agents and currently, approximately 30 platinum(II) and platinum(IV) entered into some of the phases of clinical trials. A special place in today’s research belongs to platinum complexes with diammine ligands. A large number of edda (ethylenediamine- N, N’-diacetate)-type ligands and their corresponding metal complexes has been successfully synthesized. This article summarizes recent progress in research on edda-type-platinum complexes. Some of these agents achieves better effect compared to the gold standard (cisplatin). It has been shown that there is a possible relationship between the length of the ligand ester group carbon chain and its cytotoxic effect. In most cases the longer the ester chain is the greater is the antitumor activity. Of particular interest are the noticeable effects of some new platinum compound with edda-type ligand on cell lines that are known to have a high level of cisplatin-resistance. Exanimate complexes appear to have a different mode of mechanism of action compared with cisplatin which includes apoptotic and necrotic cell death. There are indications that further investigations of these compounds may be very useful in overcoming the problems associated global cancer statistic.

Carbon Chain Growth by Sequential Reactions of CO and CO2 with a Transition Metal Carbonyl Complex

2018 ◽  
Author(s):  
Richard Kong ◽  
Mark Crimmin
Keyword(s):  
Transition Metal ◽  
Metal Carbonyl ◽  
Carbon Chain ◽  
Chain Growth ◽  
Carbonyl Complex ◽  
Fischer Tropsch ◽  
Carbon Chains ◽  
Sequential Coupling ◽  
Energy Economy ◽  
Sequential Reactions

<i>The formation of carbon chains by the coupling of COx (X = 1 or 2) units on transition metals is a fundamental step relevant to Fischer-Tropsch catalysis. Fischer-Tropsch catalysis produces energy dense liquid hydrocarbons from synthesis gas (CO and H2) and has been a mainstay of the energy economy since its discovery nearly a century ago. Despite detailed studies aimed at elucidating the steps of catalysis, experimental evidence for chain growth (Cn to Cn+1 ; n > 2) from the reaction of CO with metal complexes is unprecedented. In this paper, we show that carbon chains can be grown from sequential reactions of CO or CO2 with a transition metal carbonyl complex. By exploiting the cooperative effect of transition and main group metals, we document the first example of chain propagation from sequential coupling of CO units (C1 to C3 to C4), along with the first example of incorporation of CO2 into the growing carbon chain.</i><br>

TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lily M.G. Panggabean ◽  
Abdullah Rasyid ◽  
Zarrah Duniani ◽  
Yana Meliana ◽  
Indah Kurniasih
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Double Bond ◽  
Unsaturated Fatty Acid ◽  
Ion Trap ◽  
Carbon Chain ◽  
Highly Unsaturated Fatty Acid ◽  
Marine Diatom ◽  
Ion Trap Mass Spectrometry ◽  
Spectra Analysis

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

Participation of 19-ester groups in the cleavage of 2α,3α- and 5α,6α-steroid epoxides. A case of competition between participation and external nucleophile attack

1979 ◽  
Vol 44 (5) ◽  
pp. 1496-1509 ◽  
Author(s):  
Pavel Kočovský ◽  
Václav Černý
Keyword(s):  
Perchloric Acid ◽  
Hydrobromic Acid ◽  
Ester Group ◽  
Carbonyl Oxygen ◽  
Cyclic Carbonate ◽  
Cyclic Ether ◽  
Normal Reaction ◽  
Neighboring Group ◽  
Ether Oxygen ◽  
The Difference

Acid cleavage of the acetoxy epoxide IIIa with aqueous perchloric acid or hydrobromic acid gave two types of products, i.e. the diol Va or the bromohydrin VIa, and the cyclic ether VIII. The latter compound arises by participation of ether oxygen of the ester group. On reaction with perchloric acid the epoxide IVa gave the diol XIIIa as a product of a normal reaction and the isomeric diol Xa as a product arising by intramolecular participation of the carbonyl oxygen of the 19-acetoxy group. Participation of the 19-ester group is confirmed by the formation of the cyclic carbonate XI when the 19-carbonate IVb is treated analogously. On reaction with hydrobromic acid, the epoxide IVa gave solely the bromohydrin XIVa as a product of the normal reaction course. Discussed is the similarity of these reactions with electrophilic additions to the related 19-acetoxy olefins I and II, the mechanism, the difference in behavior of both epoxides III and IV, the dependence of the product ratio on the nucleophility of the attacking species, and the competition between participation of an ambident neighboring group and an external nucleophile attack.

Sign in / Sign up

Export Citation Format

Share Document