DI-T-BUTYLCYCLOPROPENONE AND SUBSTITUTED DI-T-BUTYLCYCLOPROPENYL CATIONS

Di-t-butylcyclopropenone (1) has been synthesized and its chemistry investigated. Pyrolysis or photolysis afforded di-t-butylacetylene. Condensation of 1 with malononitrile and ethyl cyanoacetate generated the triafulvenes 2 and 3, respectively. Substituted di-t-butylcyclopropenyl cations 5 including the tri-t-butylcyclopropenyl cation (5a) have been prepared via the reaction of 1 with organolithium reagents. The pKR+ values of these cations have been determined by potentiometric titration and are discussed. Some reactions of cation 5a are described. © 1969, American Chemical Society. All rights reserved.