| 摘要 |
<p>PURPOSE:3-Hydroxy-3-methylcephalosporin derivatives of formula I (R1 and R2 are H, amino-protecting group, or in combination may form an amino-protecting group; R3 and R4 form a primary amino, a secondary amino, or an ammonium residue in the form of -NR3R4, etc.); for example, 7-phenoxyacetamido-3-hydroxy-3-methylcepham-4-carboxylic acid-N-tert-butylamide.</p> |
