Synthese einer Calicen-Vorstufe für Retro-Diels-Alder-Reaktionen

✍ Scribed by Michel Mühlebach; Markus Neuenschwander

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: German
• Weight: 816 KB
• Volume: 77
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19940770516

✦ Synopsis

Synthesis of a Calicene Precursor for Retro‐Diels‐Alder Reactions

In view of retro‐Diels‐Alder reactions (RDA reactions), the calicene precursor 9 has been synthesized in a comparably simple four‐step synthesis by dibromocarbene addition at dibenzobarrelene (10 → 11, 44%), halogenlithium exchange followed by reaction with cyclopentenone (11→12, 91%) and H~2~O as well as HBr elimination (12→14→9, 43%) (Scheme 5). First experiments with respect to the thermal behavior of 9 show that, although RDA reaction seems to be relatively easily occurring according to the results of ‘Curie‐Point’ pyrolysis, only anthracene and no calicene 2 has been detected so far.