2,5-Bisdiazomethylfuran: A Novel Entry to the C6H4O Surface

✍ Scribed by Sander, Wolfram ;Albers, Reinhard ;Komnick, Peter ;Wandel, Holger

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 436 KB
• Volume: 1997
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199719970519

✦ Synopsis

Abstract

Warming the dilithium salt 7 of furan‐2,5‐dicarboxaldehyde bis(tosylhydrazone) to 110°C and subsequently trapping the products in solid argon at 10 K resulted in the formation of 1‐diazo‐hex‐3‐en‐5‐yn‐2‐one (9). The intermediate 2,5‐bis(diazomethylfuran) (6) is too labile to be directly observed under these conditions. The formation of 9 from 6 is rationalized by the loss of one nitrogen molecule and rapid rearrangement of the intermediate carbene 8. Photolysis of 9 leads to loss of the second nitrogen molecule and rearrangement of the resulting carbene 12. The major path is the Wolff rearrangement to hexa‐1,3‐dien‐5‐yn‐1‐one (11); the minor path is the intramolecular cycloaddition of the carbene center to the triple bond to 1__H__‐bicyclo[3.1.0]hexa‐3,5‐dien‐2‐one (2). UV photolysis of 2 results in the ring opening to yield again ketene 11. The mechanism of this rearrangement was investigated by deuterium labeling.