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The reaction of 2-(4-hydroxyphenyl)ethyl alcohol (I) with Ms-Cl and TEA in dichloromethane gives the bis-methanesulfonate (II), which is condensed with 4-hydroxybenzaldehyde (III) by means of K2CO3 in acetonitrile to yield the substituted benzaldehyde (IV). The condensation of (IV) with phosphonium salt (V) by means of tetramethylguanidine (TMG) in chloroform affords the acrylic ester (VI), which is reduced with H2 over Pd/C in ethyl acetate to provide the propionic ester (VII). The hydrolysis of (VII) with LiOH in THF/water gives the propionic acid (VIII) as a racemic mixture, which is condensed with (R)-phenylglycinol (IX) by means of EDC, HOBt and DIEA in dichloromethane to yield the amide (X) as a diastereomeric mixture that is separated by crystallization and chromatography. The desired (S)-isomer (XI) is treated with H2SO4 in hot dioxane/water to furnish the target propionic acid.