Chiral Building Blocks: Enantioselective Syntheses of Benzyloxymethyl Phenyl Propionic Acids

Abstract

Abstract:The synthesis of (2S)-2-benzyloxymethyl-3-(2-fluoro-4-methoxyphenyl)-propionic acid, (2S)-2-benzyloxymethyl-3-(2-fluoro-4-methylphenyl)propionic acid and (2S)-2-benzyl-oxymethyl-3-(2,4-dimethylphenyl)propionic acid has been achieved by TiCl 4 mediated alkylation of the corresponding (4R)-4-benzyl-3-[3-(2-fluoro-4-methoxyphenyl-, 2-fluoro-4-methylphenyl-, 2,4-dimethylphenyl-)propionyl]-2-oxazolidinones, followed by hydrolysis of the chiral auxiliary. The stereochemistry of the alkylation reaction was confirmed by an X-ray crystal structure of (4R)-4-benzyl-3-[(2S)-2-benzyloxymethyl-3-(2-fluoro-4-methylphenyl)propionyl]-2-oxazolidinone.