Effect of Substitution on the Intramolecular 1,3-Dipolar Cycloaddition of Alkene Tethered Münchnones

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• 作者：Guillaume Bé ; langer ; Myriam April ; É ; tienne Dauphin ; Sté ; phanie Roy
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：February 16, 2007
• 年：2007
• 卷：72
• 期：4
• 页码：1104 - 1111
• 全文大小：248K
• 年卷期：v.72,no.4(February 16, 2007)
• ISSN：1520-6904

文摘

BLE>bscribe/journals/joceah/72/i04/figures/jo061556tn00001.gif" ALIGN="left" HSPACE=5>A sequence of chemoselective activation of N-acylaminoacids, münchnone generation, intramolecular1,3-dipolar cycloaddition, and ring opening efficiently generated functionalized polycyclic structures suchas cyclopenta[b]pyrroles or zwitterionic bicyclo[4.3.0]nonane or bicyclo[3.3.0]octanes in one operationis given. These zwitterionic species were isolated for the first time and were subsequently reduced tobicyclic aminoalcohols. The effect of the substitution of both the dipolarophile and the münchnone onthe intramolecular cycloaddition outcome was examined. It was found that either nonactivated or electron-poor alkenes can react with the münchnone if these alkenes are tethered at position 4 on the münchnone(2, R² = alkene tether), whereas only an electron-poor alkene at position 2 (2, R³ = alkene tether) couldundergo successful cycloaddition. Also, münchnones substituted at position 2 with a phenyl (2, R³ = Ph)showed a dramatic increase in reactivity, whereas a phenyl at position 4 (2, R² = Ph) had a very limitedeffect.