[Synthetic studies on kinamycin antibiotics]

Kinamycin antibiotics, strongly active against gram-positive bacteria, were isolated from the culture broth of Streptomyces murayamaensis. The structures of kinamycins and prekinamycin, isolated from the same bacteria, were at first determined to be benzo[b]carbazole with cyanamide [N-C ≡ N]. Later re-examination of spectroscopic analysis concluded that those compounds should be benzo[b]fluorene with diazoalkane [C⁻ - N(+)≡ N]. However, the structure of the latter was re-revised to benzo[a]fluorene and renamed as isoprekinamycin. We have continued our effort for the synthesis of kinamycin antibiotics from the point of view of total synthesis and structural determination. In this review, our approach toward total synthesis of kinamycins was described.