Birch reduction of D-α-phenylglycine led to diene (2). This was N-protected using tert-butoxycarbonylazide and activated for amide formation via the mixed anhydride method using isobutylchloroformate to give 3. Mixed anhydride 3 reacted readily with 7-aminodesacetoxycephalosporanic acid to give, after deblocking, cephradine (5).