Reinvestigation of the substituent effects of fluorine on the1H NMR chemical shifts of the adjacent methylene group in fluorinated [2.2]paracyclophanes

Abstract

Introduction of a fluorine substituent into an aromatic ring of [2.2]paracyclophane causes distinct shielding and deshielding effects at the anti‐ and syn‐protons, respectively, of the adjacent bridge methylene group. A recent contradictory claim in the literature was disproved by 2D H,H‐NOESY, long‐range H,H‐COSY and H,C‐HMBC experiments. Copyright © 1999 John Wiley & Sons, Ltd.