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

AS Demir, M Emrullahoglu, E Pirkin…

Index: Demir, Ayhan S.; Emrullahoglu, Mustafa; Pirkin, Eser; Akca, Nazmiye Journal of Organic Chemistry, 2008 , vol. 73, # 22 p. 8992 - 8997

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Citation Number: 15

Abstract

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 ...