Kinamycin alkaloids

The reactions of 2-bromonaphthoquinone (221, R = H) and 3-bromo-juglone (221, R = OH) with enaminones 222 gave regioselectively benzo-[/ Jindoles or tetrahydrobenzo[/i]carbazoles 223, Scheme 59. This modification of the Nenitzescu reaction opened up new entries to the Kinamycin alkaloid framework (92TL535). 

Methods for the synthesis of tetracyclic benzocarbazoles and benzo-b-carbazoloquinone have become relevant to alkaloidal synthesis due to the progress in the chemistry of the kinamycin group antibiotics. 

A decaketide (188) cyclising to a benzoanthraquinone (189) has been shown to be precursor of the kinamycin group of alkaloids 111, 112). The benzoanthraquinone undergoes an unusual process involving oxida-lion/nitrogen insertion/ring contraction to yield prekinamycin (190). 

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