| Abstract: | An Uniformly Occurring Aliphatic Benzil-Benzilic-Acid-Type Rearrangement Treatment of 6-bromo-2,2,5,5-tetramethylcyclohex-3-enone ( 2 ) with aqueous alkaline and air affords 1-hydroxy-2,2,5,5-tetramethylcyclopent-3-enecarboxylic acid ( 8 ) as the major product of a benzil-benzilic-acid-type rearrangement. The key compound is 2,2,5,5-tetramethylcyclohex-3-ene-1,2-dione ( 11 ). The by-product of the reaction is (E)-2,2,5,5-tetramethylhex-3-enedioic acid ( 9 ) as the result of an oxidative cleavage of the 6-membered ring and the isomerization of the double bond. |
