Reduction of Some Phthalic Acid Derivatives

Abstract

Relatively unselective methods were available before 1947 for the reduction of carboxylic acids and related compounds. With the advent of complex metal hydrides some selectivity was achieved yet the immediate applications were concerned with monocarboxylic acids and derivatives. Consequently, a very challenging area of research still exists in the development of preparative methods leading to aromatic dialdehydes in which the aldehyde groups are vicinal, e.g. phthalaldehyde (I). We describe here three reductive procedures leading to I in good yields.