Syntheses of crown ether-esters with (benzyloxy)methyl side arms using SbPh3 and BiPh3 as templates1

Abstract

New crown ether-esters 3a, 3b, 4a, 4b, 4c and 5a with side arms are synthesized by the treatment of (benzyloxy)methyl-substituted diols (1 and 2) with acid chlorides [malonyl chloride and diglycolyl chloride (2,2′-oxydiacetyl chloride)]. SbPh₃ and BiPh₃ are effective templates for the synthesis of 14-crown-4 ether-esters with (benzyloxy)methyl side arms, and the template effect depends on the structures of both the diols and acid chlorides. Also, it was revealed that the key step in the template synthesis is the formation of a complex between 1 and MPh₃(M Sb and Bi) by IR and mass spectral studies. The order of complexing ability between 1 and MPh₃ is: 1 + BiPh₃ 1 + SbPh₃ > 1 + AsPh₃. In particular, BiPh₃ can form stable 1:1 and 2:1 complexes with 1.