The partial hydrolysis of 7-(phenylacetamido) cephalosporanic acid (I) followed by esterification with diphenyldyazomethane (II) gives benzhydryl 3-(hydroxymethyl)-7-(phenylacetamido)-3-cephem-4-carboxylate (III), which by reaction with PCl5 affords benzhydryl 7-amino-3-(chloromethyl)-3- cephem-4-carboxylate (IV). The condensation of (IV) with N-(tert-butoxycarbonyl)-2(R)-(4-hydroxyphenyl) glycine (V) by means of dicyclohexylcarbodiimide (DCC) yields benzhydryl 7-[(R)-2-(tert-butoxycarbonylamino)-2-(4-hydroxypheny) acetamido]-3-(chloro-methyl)-3-cephem-4-carboxylate (VI), which by reaction with NaI in acetone is converted to the corresponding iodomethyl derivative (VII).The reaction of (VII) with triphenylphosphine in ethyl acetate affords the phosphonium salt (VIII), which is submitted to a Wittig condensation with acetaldehyde to yield benzhydryl 7-[(R)-2-(tert-butoxycarbonylamino)-2-(4-hydroxyphenyl)acetamido]-3-(propenyl)-3-cephem-4-carboxylate (IX). Finally this compound is deprotected by a treatment with trifluoroacetic acid.