| 摘要 |
<p>Disclosed herein is a process for preparing 3-hydrogen cephems by electrolytically reducing a cephem of the formula wherein R is C1-C3 alkyl, phenyl, phenyl substituted with 1 or 2 hydroxy, protected hydroxy or C1-C4 alkoxy groups, -CH2R1 , or -CHR2R3 ; R1 is thienyl, tetrazolyl, phenyl, phenoxy, or phenyl or phenoxy substituted with 1 or 2 hydroxy or protected hydroxy groups; R2 is protected amino, carboxy, protected carboxy, hydroxy or protected hydroxy; R3 is 1,4-cyclohexadienyl, phenyl, thienyl, or phenyl substituted with 1 or 2 hydroxy or protected hydroxy groups; R4 is hydrogen or a carboxy-protecting group; and R5 is chloro, C1-C3 alkanesulfonyloxy or toluenesulfonyloxy; in an aqueous liquid medium at a pH from about 5 to about 8 in the presence of an electrolyte at the working electrode of an electrolytic cell, said working electrode substantially comprising mercury, lead or zinc, at a temperature from about 0.degree. to about 75.degree.C. at a potential in a range from about the potential of the initial onset of current flow of the first reduction to about the potential of the initial onset of current flow of the second reduction.</p> |
