DIELS-ALDER CYCLO-ADDITION OF JUGLONE DERIVATIVES .2. REGIOSPECIFICITY OF REACTIONS LEADING TO TETRACYCLIC ANTHRACYCLINONE SYSTEMS

The regiospecificity of the reaction of several juglone derivatives with two complex dienes derived from bicyclic dimethoxycyclobutenes has been examined as part of a series of model studies leading toward the synthesis of the anthracyclinone antibiotics adriamycin and daunorubicin. In general, regiospecificity appears governed primarily by diene polarization factors. The structural assignments have been confirmed by a single-crystal X-ray analysis of one of the tetracyclic adducts from juglone methyl ether and related by chemical interconversion. © 1979, American Chemical Society. All rights reserved.