Biomimetic synthesis of the racemic angucyclinones of the aquayamycin and WP 3688-2 types.
The first synthesis of the racemic 8-deoxy WP3688-2 angucycline antibiotic (3), with characteristic cis-hydroxy groups at C-4 a and C-12b, is reported. Key steps involve the coupling, mediated by samarium diiodide, of the bicyclic trione 37 to the tricyclic cis-diol 39. Biomimetic aldol cyclization of the corresponding dione 41 gave a mixture of the tetracyclic cis- and trans-3,4a-diols 42 and 43, which were oxidized by cerium ammonium nitrate to the quinones 45 and 3. The synthetic compounds 45 and 3 corresponded in configuration to the angucycline antibiotics aquayamicin (1) and WP 3688-2 (2), respectively.
Krohn
K
K
Fachbereich Chemie und Chemietechnik der Universität Paderborn, Germany. kk@chemie.uni-paderborn.de
Frese
P
P
Flörke
U
U
D000880:Anthraquinones / Q000138:chemical synthesis*; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D018360:Crystallography, X-Ray; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D000095602:Angucyclines and Angucyclinones
D000880:Anthraquinones; D000900:Anti-Bacterial Agents; C000100:aquayamycin; D000095602:Angucyclines and Angucyclinones