SYNTHESIS AND STRUCTURE OF TRIBENZO-19-CROWN-6 LARIAT ETHERS

Multistep preparative routes to a series of three new, proton-ionizabl e lariat ethers, sym-(R)tribenzo-19-crown-6-oxyacetic acids with R = H , C3H7, and C8H17 have been developed. The crystal structure of the sy nthetic intermediate sym-(hydroxy)(propyl)-tribenzo-19-crown-6 has bee n determined. The compound crystallized in the monoclinic space group P2(1)/c with a = 8.902(4) Angstrom, b = 10.296(5) Angstrom, c = 27.631 (9) Angstrom, beta = 97.41 degrees with a volume of 2511.4 Angstrom(3) . The calculated density is 1.268 mg/mm(3) with Z = 4. The final R val ues are R = 7.99% and R(w) = 5.17% using 1558 observed reflections [F> 3.0 sigma(F)].