Acetic acid, 2-(triphenylphosphoranylidene)-, methyl ester → 14-Bromo-2-tetradecenoic acid

Participants

Reaction Steps

To 12-bromododecanol (5 g) dissolved in methylene chloride (30 ml) were added Celite (5.0 g) and pyridinium chlorochromate (5.2 g), and the mixture was stirred at room temperature for 12 hours. Then, the reaction mixture was filtered and subjected to chromatography on a silica gel column with an eluent system of n-hexane-ethyl acetate (30:1) to give 12-bromododecanal (4.4 g). To 12-bromododecanal (4.4 g) dissolved in methylene chloride (50 ml) was added (carbomethoxymethylene)-triphenylphosphorane (6.75 g), and the mixture was stirred for 4 hours. Then, the reaction mixture was concentrated, and the residue thus obtained was subjected to chromatography on a silica gel column with an eluent system of n-hexane-ethyl acetate (30:1) to give the methyl ester of 14-bromo-2-tetradecenoic acid (4.91 g). The product was dissolved in acetonitrile (30 ml), and 1M tetra-n-butylammonium chloride in THF (27 ml) and potassium fluoride (7.6 g) were added. The mixture was heated under reflux for 12 hours. The reaction mixture was concentrated and subjected to chromatography on a silica gel column with an eluent system of n-hexane-ethylacetate 100:1 to give the methyl ester of 14-fluoro-3-tetradecenoic acid (3.3 g).

Provenance & Evidence