Synthesis of 15-, 16-, and 17-Membered Bis-C-Pivot Macrocycles Consisting of N2O2 Donor-Type Crown Ethers and Dialkyl Phosphonates

ABSTRACT Bis‐C‐pivot macrocycles containing aminophosphonate functions (5–10) have been synthesized and characterized by elemental analysis, FTIR, MS, 1D 1H, 13C and 31P NMR, and 2D HETCOR techniques. The phosphorylation reaction of dibenzo‐bis‐imino crown ethers (1–4) with dimethyl and diethyl phosphite used here has the potential to provide bis‐C‐pivot macrocycles (5–10), which possess two stereogenic C‐centers giving rise to diastereoisomers (meso and racemic). Detailed spectral assignments for the meso and racemic forms of the compounds are reported on the basis of chemical shifts, signal intensities, spin–spin coupling constants, and splitting patterns. The bis‐C‐pivot macrocycles (5–10) may serve as a potential new class of supramolecular host molecules.