A mixture of L-threonine (5 mmol, 0.595 g), sodium bicarbonate (5 mmol, 0.420 g) and succinimidyl nervonate (5 mmol, 2.320 g, prepared according to Example 1A) in water (2 mL) and dimethoxyethane (5 mL) were refluxed for 2 hours until no ester remained according to TLC (hexane-diethyl ether-acetic acid, 80:18:2). Acidification to pH 2 with concentrated hydrochloric acid and chilling gave the title product, which was washed with water, dried and crystallised from chloroform. It was finally washed with hexane to remove small amounts of non-polar contaminants.
