[doof]

What is the easiest way to substitute a carboxylic acid for a CH3 group? And preferably the safest way too

[Dan]

For R-COOH --> R-CH₃ there are a number of approaches, here are some suggestions.

Aldehydes can be reduced to alkanes (RCHO --> R-CH₃) by:

1. Wolff-Kishner - Basic
2. Clemmensen - Acidic
3. Mozingo (Raney Ni reduction of a corresponding thioacetal) - neutral

The aldehyde can be obtained from the acid by partial reduction via the ester or amide with DIBAL, or catalytic hydrogenation via the acid chloride, for example.

Alternatively, you could reduce the acid all the way down to the primary alcohol with LAH and substitute with, for example, a halide - which can then be removed by catalytic hydrogenolysis, or radically with Bu₃SnH.

[Schrödinger]

How about HI/P(red)  reduction?

It is one of those reductions of a carboxylic acid directly to CH3 group without destroying the Carbon of the COOH group like is done during decarboxylation.

[doof]

thanks

[doof]

How about HI/P(red)  reduction?

It is one of those reductions of a carboxylic acid directly to CH3 group without destroying the Carbon of the COOH group like is done during decarboxylation.

Is HI/P(red) reactive enough to reduce a carboxylic acid?

[Schrödinger]

As far as I know, yes

[orgopete]

I might be interested in that reaction also. Do you have a reference for HI/P to convert a carboxylic acid to a methyl group?

[doof]

As far as I know, yes

and how far do you know exactly? have you read a journal article showing that is works? have you done the experiment yourself? read it on the net somewhere? or just having a guess? can you please elaborate on what convinces you that it will work?

[Schrödinger]

@doof : See http://www.tutorvista.com/content/chemistry/chemistry-iv/oxygen-ii/carboxylic-acids-reduction.php

[doof]

cheers man