Long‐range deuterium isotope effects on ¹³C NMR shifts of intramolecularly hydrogen‐bonded 9‐hydroxyphenalen‐1‐ones

Abstract

Abstract The 1 H and 13 C NMR spectra of 9‐hydroxyphenalenone (1) and 9‐hydroxy‐2‐methylphenalenone (2) have been completely assigned. Primary and secondary deuterium isotope effects were determined in three solvents (chloroform, acetone and dimethyl sulphoxide), including the effect of temperature on the secondary isotope effects. Both negative and large long‐range secondary isotope effects were found for both 1 and 2. The average secondary isotope effects for corresponding carbons follow the same sign and magnitude pattern in both compounds.