Reduction of 4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzaldehyde (I) with NaBH4 affords alcohol (II). Subsequent chlorination of (II) employing thionyl chloride in toluene leads to the benzyl chloride (III)

Friedel-Crafts acylation of diphenyl ether (IV) with ethyl chloroglyoxylate (V) affords the (4-phenoxyphenyl)glyoxylate (VI). This is then treated with hydroxylamine to produce a mixture of Z- and E-oximes (VII) and (VIII), which can be separated by recrystallization, followed by column chromatography. The desired Z-oxime (VII) is alkylated by the benzyl chloride derivative (III) to furnish the O-benzyl oxime (IX). Finally, saponification of the ethyl ester group of (IX) with NaOH in MeOH gives rise to the target carboxylic acid

Reduction of 4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzaldehyde (I) with NaBH4 affords alcohol (II). Subsequent chlorination of (II) employing thionyl chloride in toluene leads to the benzyl chloride (III)

Friedel-Crafts acylation of diphenyl ether (IV) with ethyl chloroglyoxylate (V) affords the (4-phenoxyphenyl)glyoxylate (VI). This is then treated with hydroxylamine to produce a mixture of Z- and E-oximes (VII) and (VIII), which can be separated by recrystallization, followed by column chromatography. The desired Z-oxime (VII) is alkylated by the benzyl chloride derivative (III) to furnish the O-benzyl oxime (IX). Finally, saponification of the ethyl ester group of (IX) with NaOH in MeOH gives rise to the target carboxylic acid