UC Irvine

The structure of the first isolable alkaline hydrolysis product of 3,3-dimethyl-1,1,2,2-tetracyanocyclopropane (I) is confirmed as the acid-amide-imide II. Thermal decarboxylation of II proceeds with cleavage of the cyclopropane ring, and probably involves participation by the neighboring eis-carboxamido group; mechanisms which would allow decarboxylation without ring opening would require highly strained transition states. Two additional examples of decarboxylation of a cyclopropanecarboxylic acid with ring cleavage are presented. Compound II was converted in four steps and high yield by alternate methylation with diazomethane and hydrolysis with base to the corresponding cyclopropanetetracarboxylic acid (XIII). One of the hydrolytic steps (X → XI) involves a remarkable transformation in which a five-membered imide ring between cis substituents is hydrolyzed on one side of the cyclopropane ring plane and formed on the opposite side. © 1963, American Chemical Society. All rights reserved.