合成路线1

Ethyl phenylacetate (V) was dimethylated upon treatment with iodomethane and sodium bis(trimethylsilyl)amide, yielding (VI). Iodination of (VI) was carried out by means of iodine and sodium iodate in acidic medium, and the resulting iodo ester (VII) was subsequently hydrolyzed with KOH to the carboxylic acid (VIII). This was converted to the tert-butyl ester (X) via conversion to the corresponding acid chloride (IX) with oxalyl chloride, followed by treatment with potassium tert-butoxide. Palladium-catalyzed Heck coupling of aryl iodide (X) with N-Boc-dehydroalanine benzyl ester (XI) furnished the aminocinnamic acid derivative (XII). Then, catalytic hydrogenation of the olefin double bond of (XII) with simultaneous benzyl ester cleavage provided the protected racemic amino acid intermediate (XIII).