Syntheses of crown ether-esters with (benzyloxy)methyl side arms using SbPh(3) and BiPh(3) as templates

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)]. SbPh(3) and BiPh(3) 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 MPh(3) (M = Sb and Bi) by IR and mass spectral studies. The order of complexing ability between 1 and MPh(3) is: 1 + BiPh(3) much greater than 1 + SbPh(3) > 1 + AsPh(3). In particular, BiPh(3) can form stable 1:1 and 2:1 complexes with 1.