| 摘要 |
Cephalcsporin derivs. (I; R3 = H, methoxy; R1 = III, IV, V; n = 2-9; R16, R19 = lower alkyl, aralkyl; R20 = H, α-halo, α,α=dihalo C2-4 alkanoyl)were prepd. by hydrolysis of iminoether. The imino-ether was prepd. by treating silylester of compd.(II) with PCI5 followed by treating with methanol. Thus, the mixt. of D-(-)-α-formylcxy methyl acetyl chloride. 1.5g, 7-amino-3-(l-carboxyethyltetrazol-5-ylthiomethyl)- 3-cephem-4-carboxylic acid 1.6 g, sodium bicarbonate 2.1 g, and H2 25ml was reacted for 1 hr, acidified, and vacuum dried to give compd.(I) 500mg.
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