Synthesis of the first examples of p-bromodienone and transannular spirodienone calixarene derivatives

The first examples of p-bromodienone calixarene derivatives (6–7 and 9–10) have been obtained by treatment of 1,5-dihydroxy-hexaalkoxycalix[8]arenes 5 or tripropoxycalix[4]arene 8 with trimethylphenylammonium tribromide and a saturated solution of NaHCO3. The first transannular spirodienone derivative 11 was only obtained in the presence of NaOH or using the KOH/I2/PEG-200 oxidizing system.