# Is there any method to synthesize salicylaldehyde from salicylic acid?

I know salicyclic acid can be produced from salicaldehyde by treatment with $\ce{KMnO4}$.

Is there any way to reverse this, i.e- produce salicaldehyde from salicyclic acid?

• There are reducing agents available that would reduce carboxylic acids. Trouble is that aldehydes are usually more reactive than acids, thus you often get the alcohol. But that can be selectively oxidized to the aldehyde and given the cheap starting material, the two-step procedure should be fine. Nov 30 '17 at 8:21

Salicylic acid can be converted to salicylaldehyde using a triangular or square wave alternating voltage. The process of this conversion is explained in this paper$\ce{^{1}}$but it is behind paywall so here's the abstract: