7-Methyl-tricyclo[5.3.0.0.1,6]deca-2,4-dien-8-ones: The first examples of tricyclonorcaradienones in tautomeric equilibrium with the 7-methyl-bicyclo[5.3.0]1,3,5-decatrien-8-ones

Article abstract of DOI:10.1016/S0040-4039(00)97700-1

Introduction of a methyl group at the C₇ position of bicyclo[5.3.0.] 1,3,5-decatrien-8-one results in a stabilization of the norcaradienic structure which causes equilibrium between the two cyclotautomers whose populations were determined.