Acid-catalysed rearrangements of 3,5-dimethyl-1-methoxy-tetrafluorobenzobarrelene (5,6,7,8-tetrafluoro-1,4-dihydro-3,10-dimethyl-1-methoxy-1,4-ethenonaphthalene)
Abstract
The title compound undergoes rearrangement in trifluoroacetic acid to afford almost exclusively the benzobarrelenone (2) whereas in concentrated sulphuric acid the lactone (3) is obtained in quantitative yield.