Pd(O) promoted rearrangement of 2-(1,3-butadienyl)cyclopropane- 1,1-dicarboxylate esters to 2-alkenyl-3-cyclopentene-1,1-dicarboxylate esters

✍ Scribed by Yoshitomi Morizawa; Koichiro Oshima; Hitosi Nozaki

• Book ID: 104221754
• Publisher: Elsevier Science
• Year: 1982
• Tongue: French
• Weight: 233 KB
• Volume: 23
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)88436-1

✦ Synopsis

The title dienylcyclopropanes smoothly rearrange to five-membered rings in the presence of a Pd(0) catalyst under mild conditions. Although the vinylcyclopropane-cyclopentene rearrangement' has attracted mechanistic interest, the synthetic application has been limited because of the high temperature (300-500°C) required.2 Here we wish to describe that dienylcyclopropanes activated by two electron-withdrawing groups easily rearrange to vinylcyclopentene derivatives in the presence of a catalytic amount of Pd(0) at 25-60°C. To a solution of dienylcyclopropane I (0.24 g, 1.1 mnol) in DMS03 (3.0 ml), Pd(PPh3)44 (30 mg, 0.03 nrnol) was added under argon atmosphere. The mixture was heated at 50°C for 15 min. The resulting yellow solution was diluted with ether (5.0 ml) and washed with brine. After ether extraction (5 mlx2), the combined organic solution was dried (Na2S04),

Table 1. Pd(0) Catalyzed Rearrangement of Dienylcyclopropanesa Entry Substrateb Temp(