Reductive dimerization of alkylidenemalonates using samarium(II) diiodide and 1H-NMR behavior of the dimers, 2,3-diaryl-1,1,4,4-butanetetracarboxylates.
Alkylidenemalonates were readily dimerized in the presence of SmI2 to give 2,3-disubstituted 1,1,4,4-butanetetracarboxylates as mixtures of meso and racemic isomers in moderate to good yields. The structure of the less polar isomer of tetraethyl 2,3-diphenyl-1,1,4,4-butanetetracarboxylate was determined by X-ray crystallographic analysis to be the meso form. Characteristic 1H-NMR behavior of the meso and racemic isomers is also discussed.
Yamashita
M
M
Kyoto Pharmaceutical University, Japan. yamasita@mb.kyoto-phu.ac.jp
Okuyama
K
K
Kawasaki
I
I
Nakamura
S
S
Nagamine
R
R
Tsujita
T
T
Ohta
S
S
D002073:Butanes / Q000138:chemical synthesis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D007202:Indicators and Reagents; D007454:Iodides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008314:Malonates / Q000737:chemistry*; D015394:Molecular Structure; D012493:Samarium / Q000737:chemistry*
D002073:Butanes; D002264:Carboxylic Acids; D007202:Indicators and Reagents; D007454:Iodides; D008314:Malonates; D012493:Samarium; C409809:samarium diiodide