An efficient conversion of carboxylic acids to one-carbon degraded aldehydes via 2-hydroperoxy acids.

After the formation of dianions of a carboxylic acid with lithium diisopropylamide, oxygen was bubbled into the solution to produce 2-hydroperoxy acid. Then the reaction mixture was acidified with a 2 N HCl solution and subsequently elevated to 50 degrees C to afford the aldehyde with the loss of one carbon atom. Even saturated (C(10)-C(20)) and unsaturated (C(18:1)) carboxylic acids were converted into the odd aldehydes (C(9)-C(19), C(17:1)) in high yields. This conversion was found to be an efficient method for the preparation of carboxylic acids (Cn) to one-carbon degraded aldehydes (Cn-1) via 2-hydroperoxy acids.