Ein alternativer Zugang zum PQQ-Triester

✍ Scribed by Dieter Sicker; Ekkehard Stehfest; Horst Wilde; Pierre Martin

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: German
• Weight: 280 KB
• Volume: 79
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19960790309

✦ Synopsis

An Alternative Approach to the PQQ‐Triester

A novel approach to triethyl 5‐methoxy‐1__H__‐pyrrolo[2,3‐f]quinoline‐2,7,9‐tricarboxylate (6), a close precursor of the redox cofactor PQQ of bacterial dehydrogenases, is described. Diethyl 2‐oxopent‐3‐ynedioate (5) was used as building block for the annelation of the quinoline unit. The annelation proceeds in two steps via the diastereoselective formation of diethyl (Z)‐4‐{[2‐(ethoxycarbonyl)‐5‐methoxyindol‐6‐yl]amiono}‐2‐oxopent‐3‐enedioate ((Z)‐7) followed by acid‐catalyzed cyclocondensation.