A simple synthesis of ketone from carboxylic acid using tosyl chloride as an activator

cis-Diastereoselective Synthesis of Spirooxindolo-β-Lactams by Staudinger Cycloaddition with TsCl as Activating Co-reagent

A convenient and versatile one-pot method for synthesis of 1,3-bis-aryl spirooxindolo-β-lactams from isatin Schiff bases and substituted phenylacetic acids using ketene-imine cycloaddition reaction with TsCl for a ketene generation has been developed. The reaction procedure does not require absolute solvents and unstable starting reagents. The studied reactions lead to cis-diastereoselective β-lactam formation for all tested phenylacetic acids except 4-MeOC6H4CH2COOH. An increase of trans-diastereomers yields with increasing temperature and solvent polarity was demonstrated.

One Pot Conversion of Carboxylic Acid to Ketone Using Trimethylsilyl Chloride

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.

Exploration of Mesyl Chloride in a One Pot Conversion of Carboxylic Acids to Ketones

Background:

Due to the ubiquitous nature of the ketone functionality, it is considered an important functional group in organic chemistry. Hence, the synthesis of ketones from readily available starting materials is an important chemical transformation in organic synthesis. Consequently, several research efforts have been reported in the literature for the transformation of carboxylic acids to ketones in a one-pot synthesis. However, some of the procedures have limitations, such as long reaction times, harsh reaction conditions, and usage of expensive metal catalysts. Thus, a simple and convenient one-pot conversion of carboxylic acids to ketones remains desirable.

Objective:

We intended to develop a simple and convenient one-pot methodology for the synthesis of ketones from carboxylic acids. Our objective was to build up a carboxylic acid-based chemical template where various types of organometallic reagents can interact to produce the desired ketone.

Methods:

In this procedure, a carboxylic acid was converted to a mixed anhydride using mesyl chloride in the presence of a base. This mixed anhydride was then reacted with a suitable organometallic reagent at -20°C to obtain the desired ketone. The reaction was performed in a one-pot fashion.

Results:

Under the optimized reaction conditions, various aromatic and heteroaromatic carboxylic acids were converted to the corresponding ketones using organolithium and organomagnesium reagents with short reaction times. Moderate to good yields of the desired ketones were observed in many of these transformations.

Conclusion:

A simple and convenient one-pot method for the conversion of carboxylic acids to ketones has been reported. Specifically, various aromatic and `heteroaromatic carboxylic acids have been converted to the corresponding ketones in moderate to good yields. Organomagnesium and organolithium reagents were used as nucleophiles for this reaction.