Dec-9-enyl bromide (CAS NO.: ), which is also known as 1-, 10-bromo-, could be produced through the following synthetic routes.

N-(10-Undecenoyloxy)pyridine-2-thione (3) . To an oven-dried, one-necked, 250-mL, round-bottomed flask equipped with a nitrogen inlet with gas bubbler, a magnetic stirrer, and a dropping funnel are added 3.61 g (28.4 mmol) of N-hydroxythiopyridone (2), 6.20 g (30.0 mmol) of dicyclohexylcarbodiimide, and 40 mL of methylene chloride. The resulting homogeneous solution is cooled to 0°C and 4.99 g (27.1 mmol) of 10-undecenoic acid (1) is added dropwise. Following the addition of the undecenoic acid, the ice bath is removed and the reaction mixture is allowed to warm to room temperature and stirred for a further 8 hr. The bright yellow suspension that results is filtered through a bed of silica gel. The solvent is removed under reduced pressure to give 8.06 g of the crude Barton ester (3).

Dec-9-enyl bromide (4). To an oven-dried, one-necked, 250-mL, round-bottomed flask equipped with a nitrogen inlet with gas bubbler, magnetic stirrer and a condenser are added 8.06 g (27.1 mmol) of the Barton ester (3) , 100 mL of methylene chloride, and 3 mL (30.0 mmol) of bromotrichloromethane. The reaction mixture is photolyzed with a 250W tungsten lamp under reflux for 30 min. The color of the reaction mixture changes from bright yellow to pale yellow. The reaction mixture is cooled to room temperature and the solvent is removed under reduced pressure. The crude product is purified by flash column chromatography (hexanes) until all the bromide 4 is eluted, affording 5.81 g of dec-9-enyl bromide (98%).

Notice: Barton esters are light sensitive; therefore all procedures should be carried out in the absence of light.