Unusual transfoemation of trimethylsilyl ester of 5-chloromethyl-2-isoxazoline-3-carboxylic acid

1981 ◽  
Vol 30 (12) ◽  
pp. 2350-2351
Author(s):  
S. L. Ioffe ◽  
Yu. D. Kuznetsov ◽  
V. A. Tartakovskii
Keyword(s):  
Carboxylic Acid ◽  
Trimethylsilyl Ester

One Pot Conversion of Carboxylic Acid to Ketone Using Trimethylsilyl Chloride

2020 ◽  
Vol 07 ◽  
Author(s):  
Habtamu Gelaw Mekonnen ◽  
Samaresh Jana
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Organometallic Reagent ◽  
Trimethylsilyl Ester ◽  
Reaction Conditions ◽  
One Pot ◽  
Simple Process ◽  
Organolithium Reagents

Background: Ketone is abundant in many natural products and in pharmaceuticals. It is believed to be one of the important functional groups in organic chemistry. Till date,several research approaches have been made to access ketone from a readily available starting materials. One such notable transformation consists of the conversion of carboxylic acid to the corresponding ketone in a one pot manner. Objective: We aimed to develop a simple one pot reaction for the conversion of carboxylic acid to ketone. This reaction could be useful to convert all types of carboxylic acid to ketone in a facile manner. Methods: In this procedure, a carboxylic acid has been converted to the corresponding trimethylsilyl ester using trimethylsilyl chloride in the presence of a base. A suitable organometallic reagent can interact with the ester formed at 20°C to produce the corresponding ketone. Results: Under the optimized reaction conditions, various aromatic, aliphatic and heteroaromatic carboxylic acids have been converted to the corresponding ketones using organolithium reagents, in a one pot manner. Moderate to good yields of the desired ketones were observed in most of the transformations. Conclusion: Conversion of carboxylic acid to ketone has been reported in a one pot fashion, where carboxylic acid has been transformed to its silyl ester. Organolithium reagents were used as nucleophile for our reaction purpose, whereas the organomagnesium reagents were not useful for this transformation. Aliphatic, aromatic and heteroaromatic carboxylic acids have been converted to the ketones following a simple process.

Fibrinolytic Activity of Cerebro-Spinal Fluid and the Development of Artificial Cerebral Haematomas in Dogs

1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto
Keyword(s):  
Cerebrospinal Fluid ◽  
Carboxylic Acid ◽  
Fibrinolytic Activity ◽  
Clinical Implications ◽  
Trans Form ◽  
Plate Method ◽  
Blood Samples ◽  
Fibrin Plate ◽  
The Brain

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

Ketones from Nickel-Catalyzed Decarboxylative, Non-Symmetric Cross-Electrophile Coupling of Carboxylic Acid Esters

2019 ◽  
Author(s):  
Jiang Wang ◽  
Brian P. Cary ◽  
Peyton Beyer ◽  
Samuel H. Gellman ◽  
Daniel Weix
Keyword(s):  
Carboxylic Acid ◽  
Solid Support ◽  
Reaction Conditions ◽  
Decarboxylative Coupling ◽  
New Strategy ◽  
The Cross ◽  
Acyl Donors ◽  
Acid Esters

A new strategy for the synthesis of ketones is presented based upon the decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with S-2-pyridyl thioesters. The reactions are selective for the cross-coupled product because NHP esters act as radical donors and the thioesters act as acyl donors. The reaction conditions are general and mild, with over 40 examples presented, including larger fragments and the 20-mer peptide Exendin(9-39) on solid support.

Harnessing Applied Potential: The Anti-Markovnikov Hydrocarboxylation of Substituted Olefins

2019 ◽  
Author(s):  
Anas Alkayal ◽  
Volodymyr Tabas ◽  
Andrei V. Malkov ◽  
Benjamin Buckley
Keyword(s):  
Carboxylic Acid ◽  
Applied Potential ◽  
Markovnikov Addition

<div>The construction of carboxylic acid compounds in a selective fashion, from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, anti-Markovnikov addition to styrenes are underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of substituted alkenes.</div>

Harnessing Applied Potential: The Anti-Markovnikov Hydrocarboxylation of Substituted Olefins

2019 ◽  
Author(s):  
Anas Alkayal ◽  
Volodymyr Tabas ◽  
Andrei V. Malkov ◽  
Benjamin Buckley
Keyword(s):  
Carboxylic Acid ◽  
Applied Potential ◽  
Markovnikov Addition

<div>The construction of carboxylic acid compounds in a selective fashion, from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, anti-Markovnikov addition to styrenes are underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of substituted alkenes.</div>

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