Synthesis of di-, tetra, and hexadeuterated 11-octadecenoates

Methyl esters of 11-octadecenoic-15, 16-d2, −15, 15, 16, 16-d4, and −10, 10, 15, 15, 16, 16-d6 acids were prepared by Wittig synthesis from intermediates derived from 11-bromoundecanoic acid and 7-chloro-3-heptyne. The dideuterated acid was prepared by partial hydrogenation of the heptyne followed by saturation with deuterium to 1-chloroheptane-4, 5-d2 for Wittig synthesis. Saturation of the heptyne with deuterium provided the Wittig intermediate for tetradeuterated acids. The hexadeuterated acids were prepared from tetradeuterated alkyl halide and 10-formyldecanoate-10, 10-d2.