(E) Enol ethers from the stereoselective reduction of α-alkoxy-β-ketophosphonates and Wittig type reaction  

作　　者：DAYOUB Wissam DOUTHEAU Alain 

机构地区：[1]Laboratoire de Catalyse et Synthèse Organique,Institut de Chimie et Biochimie Moléculaires et Supramoléculaires(ICBMS),CNRS,UMR5246,Université Lyon 1 [2]Institut National des Sciences Appliquées de Lyon,Laboratoire de Chimie Organique et Bioorganique,ICBMS UMR 5246 CNRS Université Lyon 1 INSA Lyon

出　　处：《Science China Chemistry》2010年第9期1937-1945,共9页中国科学（化学英文版）

摘　　要：When α-alkoxy-β-ketophosphonates,prepared by the Rh(Ⅱ) mediated insertion reaction of α-diazo-β-ketophosphonates into the OH bond of primary alcohols,were reduced either by NaBH4 in the presence of CaCl2 or by DIBAL,they respectively gave the corresponding anti or syn stereomeric hydroxyphosphonates with pronounced to complete stereoselectivity.Submitted to the action of potassium tert-butoxyde,syn isomers led to the corresponding pure(E) enol ethers in moderate to good yields.Under the same conditions anti isomers led to a mixture of(Z) and(E) enol ethers in rather poor yields.The sequence was applied to the preparation of some allyl-vinyl ethers with a(E) configuration for the vinylic double bond.When α-alkoxy-β-ketophosphonates,prepared by the Rh(Ⅱ) mediated insertion reaction of α-diazo-β-ketophosphonates into the OH bond of primary alcohols,were reduced either by NaBH4 in the presence of CaCl2 or by DIBAL,they respectively gave the corresponding anti or syn stereomeric hydroxyphosphonates with pronounced to complete stereoselectivity.Submitted to the action of potassium tert-butoxyde,syn isomers led to the corresponding pure(E) enol ethers in moderate to good yields.Under the same conditions anti isomers led to a mixture of(Z) and(E) enol ethers in rather poor yields.The sequence was applied to the preparation of some allyl-vinyl ethers with a(E) configuration for the vinylic double bond.

关 键 词：α-alkoxy-β-ketophosphonates reduction INSERTION rhodiocarbenoids Wittig-Wadsworth-Emmons ENOL ETHERS 

分 类 号：O621.25[理学—有机化学]