Abstract
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 ring-opening 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.
Original language | English |
---|---|
Pages (from-to) | 711-722 |
Number of pages | 12 |
Journal | Heterocycles |
Volume | 32 |
Issue number | 4 |
DOIs | |
State | Published - Apr 1 1991 |