Tritium labelling and tritium N.M.R. II. Labelled methyl (Z)-Octadec-9-enoate obtained by partial hydrogenation on Lindlar catalyst, and its reduction to(Z)-Octadec-9-en-1-ol

Abstract

The selectivity of tritium labelling of double bonds by partial hydrogenation of the acetylenic analogue on Lindlar catalyst is investigated by ³H and ¹³C n.m.r. Examples of both the secondary isotope effect on chemical shift and the usefulness of ³H n.m.r, measurements to calculate proton-proton coupling constants are described. In the absence of proton coupling a finite difference (0.014 ppm) in the chemical shift of tritons at positions 9 and 10 of methyl (Z)-[9,10-³H]octadec-9-enoate is observed.