- Improved routes to homologated isoxazoles
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Two carbon homologation of isoxazole-4-carbinols was performed by reaction of lithio-2,4,4-trimethyl-Δ2-oxazoline 1 with 4-chloromethyl-isoxazole 2, followed by trans-esterification and reduction to the isoxazole-4-propanols 5a and b. Alternati
- Meikrantz,Smith,Xia,Natale
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p. 399 - 407
(2007/10/02)
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- PREPARATION OF CROWN ETHERS WITH ISOXAZOLYL-LARIATS: HOMOLOGATION OF ISOXAZOLE ALDEHYDES, AND A CRITICAL COMPARISON OF LARIAT FUNCTIONAL MOIETIES FOR LANTHANIDE EXTRACTION
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A critical comparison of several lariat ether functional moieties is presented.The synthesis of two isoxazolyl-lariat ethers is described.The lariat ether (2, n=1) undergoes β-fragmentation on electron transfer reductive ringopening with samarium diiodide.The isoxazole moiety was then homologated to overcome this problem, and isoxazole lariat ether (2, n=3) was obtained.The isoxazole (2, n=3) and β-diketone (3, n=3) crowns were evaluated in lanthanide shift studies and liquid-liquid extraction studies.Finally, lateral metalation and electrophilic quenching with carbon dioxide produced the carboxylic acid (12) which proved to be an efficient ligand for the liquid-liquid extraction of lanthanides.
- Xia, Xiong Bing,Munsey, Mark S.,Du, Hongshan,Wai, Chien M.,Natale, Nicholas R.
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p. 711 - 722
(2007/10/02)
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