Synthetic Studies on the Kinamycin Family of Antibiotics: Synthesis of 2-(Diazobenzyl)-p-naphthoquinone, 1,7-Dideoxy-3-demethylprekinamycin, and 1-Deoxy-3-demethylprekinamycin.

2-(Diazobenzyl)-p-naphthoquinone was synthesized from 2-benzyl-1,4-dimethoxynaphthalene by cerric ammonium nitrate oxidation to 2-benzyl-p-naphthoquinone followed by diazo transfer with tosyl azide. 1,7-Dideoxy-3-demethylprekinamycin was prepared from 1,4-dimethoxynaphthalene by bromination, lithiation, and condensation with acetanthranil to give 2-(2'-N-acetaminobenzoyl)-1,4-dimethoxynaphthalene, which, following deacylation, was subjected to Pschorr cyclization to give 1,3,7-trihydro-O,O-dimethylkinafluorenone. This was then demethylated, subjected to hydrazinolysis, and then oxidized with Fetizon's reagent to complete the synthesis. 1-Deoxy-3-demethylprekinamycin was synthesized from 3-bromo-1,5-dimethoxy-4-naphthol by an identical route.