Synthesis of tetrahydroazocino- and dihydroazepino-1, 2-benzoquinones via amino-claisen rearrangement of 4- (2-vinyl - azetidino and aziridino)-1, 2-benzoquinones
Amino-Claisenrearrangement of 4-(2-vinyl- azetidino or aziridino)-5-methoxy-1,2-benzoquinones 3a,b selectively gives rise to the new tetrahydroazocino — quinone 4a or dihydroazepino — quinone 4b respectively. Based on paramethoxyphenol as starting material, overall yields for the 3 steps synthesis of heterobicyclic quinones 4a,b are 58 and 52%.