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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 31, Number 10
BKCSDE 31(10)
October 20, 2010 

 
Title
A New Synthesis of Triphenylphosphorane Ylide Precursors to α-Keto Amide/Ester and Tricarbonyl Units via Horner-Wadsworth-Emmons Reaction
Author
Kieseung Lee
Keywords
α-Keto amide, α-Keto ester, Vicinal tricarbonyl, Triphenylphosphorane ylide, Horner-Wadsworth-Emmons reaction
Abstract
Newly developed Horner-Wadsworth-Emmons (HWE) reagents 5 having triphenylphosphorane ylide subunits readily condensed with various carbonyl compounds under mild reaction conditions to afford β,γ-unsaturated α-keto triphenylphorane ylides in good to excellent yields, which were hydrogenated over Pd-C (10%)/H2 (1 atm) to give the corresponding α-keto triphenylphorane ylides in quasi-quantitative yields. These triphenyphosphorane ylides have been utilized as the precursors to α-keto amide/ester and vicinal tricarbonyl units in Wasserman’s synthetic protocols, and have previously been prepared only from carboxylic acids/acid chlorides. Our new approaches provide excellent alternatives for the synthesis of triphenylphosphorane ylide precursors to α-keto amide/ester and vicinal tricarbonyl units directly from carbonyl compounds in good to excellent yields.
Page
2776 - 2782
Full Text
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