Abstract: ¹H and ¹³C NMR spectra of 3'(, 3")-(di)-formyl-(di)-benzo crown ethers (1~7) and 4'-formyl-benzo-15-crown-5(8) were recorded and assigned firstly by combination of ¹H-¹H COSY, ¹³C-¹H COSY and COLOC 2D NMR experiments. The structures of Crown 4 and Crown 5-the synthetic products were determined by ¹H-¹H NOESY spectra and rudimentary discussion was given for the conformational isomers of Crown 4. Referred to the ¹H, ¹³C chemical shifts of Crown 1~8a general rule is proposed for the assignment of ¹H, ¹³C chemical shifts of the methylenes of benzo crown ethers.

Key words: ¹H NMR, ¹³C NMR, 2D NMR, Benzo crown ethers