Oxidation of 4,6,8-Trimethylazulene and Guaiazulene with Hydrogen Peroxide in Pyridine

Article abstract of DOI:10.1246/bcsj.64.3497

Oxidation of 4,6,8-trimethylazulene (1) with hydrogen peroxide in pyridine at 25 deg C for 18 h gave 4,6,8-trimethyl-1,5- and -1,7-azulenequinones, their 2-(4,6,8-trimethyl-1-azulenyl) derivatives, and 2,3-dihydro-4,6- and -4,7-dimethyl-2-(4,6,8-trimethyl-1-azulenyl)-1H-inden-1-ones in much higher yields than those by autoxidation of 1 in DMF at 120 deg C.The same oxidation of guaiazulene afforded sixteen separable products, among which there were three new dimeric condensates.