合成路线1

The cyclization of the 3-oxoglutarate (I) with the alkynal (II) gives the benzoate derivative (III), which is treated with CH3I and NaH to yield the dimethoxy benzoate (IV). The reduction o the formyl group of (IV) by means of NaBH4 affords the hydroxymethyl derivative (V), which is treated with MsCl and TEA to provide the mesylate (VI). The reduction of the mesylate group of (VI) by means of NaBH4 gives the methyl derivative (VII), which is cyclized by means of K2CO3 to yield the isobenzofuranone (VIII). The ozonolysis of the dimethylvinyl group of (VIII) affords the aldehyde (IX), which is oxidized with CrO3 to provide the carboxylic acid (X). The reaction of (X) with diazomethane gives the corresponding methyl ester (XI), which selectively demethylates with BCl3 in CH2Cl2 to yield mycophenolic acid methyl ester (XII). Finally, this compound is hydrolyzed with LiOH to provide the target carboxylic acid.