ChemInform Abstract: Functionalized Alkylidenecyclopentenes by Acid-Catalyzed Electrocyclic Ring Closure of (2Z)-(Di)vinylallene Acetals.

✍ Scribed by A. R. DE LERA; J. GARCIA REY; D. HROVAT; B. IGLESIAS; S. LOPEZ

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 30 KB
• Volume: 29
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199805146

✦ Synopsis

Functionalized Alkylidenecyclopentenes by Acid-Catalyzed Electrocyclic Ring Closure of (2Z)-(Di)vinylallene Acetals. -Unexpectedly, attempted acid-mediated deprotection of the (2Z)-vinylallene acetals (I) to the corresponding aldehydes results in cyclization to the cyclopentene derivatives (II) and (III). The (2Z) geometry is necessary for the rearrangement since the (2E) isomer of (Ia) cleanly yields the corresponding aldehyde. -(DE