Synthesis of mixed aza, oxa and thia crown ethers

Two series of monoaza-15-crown-5 compounds containing either a fused benzo group or sulfur donor atoms in the macrocycles have been synthesised by 1:1 cyclisation of diols or dithiols with ditosylates in the presence of sodiu m hydride; the molecular structure of 2,3-benzo-10-N- (4'-methoxyphenyl)-1, 4,7,13-tetraoxa-10-azacyclopentadecane (8) has also been determined by sing le-crystal X-ray analysis.