Large‐scale preparation of linoleic acid‐d2‐enriched triglycerides fromCrepis alpina seed oil

Catalytic deuteration ofCrepis alpina seed oil provided a convenient one‐step method for the direct synthesis of large quantities of triglycerides enriched with deuteriumlabelled linoleic acid.Crepis alpina seed (19 kg) was crushed, and the oil [74% crepenynic acid (cis‐9‐octadecen‐12‐ynoic acid)] was extracted with hexane. After purification by column chromatography (silica gel), > 170‐g batches of oil were deuterated with Lindlar catalyst and deuterium (D2) gas. Purification (silica gel) resulted in > 150‐g samples of triglyceride containing 74%cis‐9,cis‐12‐octadecadienoic acid‐12,13‐d2 (18:2‐d2) and 14% unlabelled linoleic acid. Pure (> 99%) tricrepenynin was recovered by further fractionation of theCrepis alpina triglycerides on silica gel. Deuteration of this sample produced deuteriumlabelled trilinolein containing linoleic acid‐d2 of > 98% isotopic purity.