The Reaction of 1,3‐Butadiene with Ethyl Diazopyruvate. Syntheses of Salicylates and of Nezukone

Abstract

Abstract The Rh‐catalyzed reaction of 1,3‐butadiene with ethyl 3‐diazopyruvate leads, inter alia , to a dihydro‐oxepinecarboxylate whose oxidation and functinal‐group manipulation produce salicylates. Wittig reactions on the acylcyclopropane accompanying the dihydrooxepine yields acrylates whose pyrolyses afford cycloheptadiene‐carboxylates. Oxidation and functional‐group transformation produces the natural tropone, nezukone.