Darzens Reaction of Acyl Phosphonates with α-Bromo Ketones: Selective Synthesis of cis- and trans-Epoxyphosphonates

详细信息    查看全文

• 作者：Ayhan S. Demir ; Mustafa Emrullahoglu ; Eser Pirkin ; Nazmiye Akca
• 刊名：Journal of Organic Chemistry
• 出版年：2008
• 出版时间：November 21, 2008
• 年：2008
• 卷：73
• 期：22
• 页码：8992-8997
• 全文大小：245K
• 年卷期：v.73,no.22(November 21, 2008)
• ISSN：1520-6904

文摘

Acyl phosphonates with α-halo ketones in the presence of bases at room temperature afford cis- and trans-epoxyphosphonates in good chemical yields and high selectivities using different bases. The diastereoselectivity of this reaction is easily controlled by changing the base. Changing the base from Cs₂CO₃ to DBU changed the diastereomeric ratio (trans/cis) from 3/2 to 9/1. Moreover, the treatment of the trans isomer with DBU showed a complete conversion to the corresponding cis isomer.