Preparation of delta 3-7 alpha-phenylacetamidodesacetoxycephalosporanic acid.
J Antibiot (Tokyo)
; 32(8): 820-7, 1979 Aug.
Article
in En
| MEDLINE
| ID: mdl-500502
ABSTRACT
delta 3-7 alpha-Phenylacetamidodesacetoxycephalosporanic acid was prepared by ring expansion of 6-epi-benzylpenicillin-S-sulfoxide, using N,O-bis(trimethylsilyl)acetamide (BSA) as silylating and dehydrating agent and alpha-picoline/alpha-picoline hydrobromide as catalyst. In some experiments 7 alpha-phenylacetamido-3 beta-bromo-3 alpha-methylcepham-4 alpha-carboxylic acid was obtained as a side product. 7-Epimers in the desacetoxycephalosporanic series were also prepared by base-catalyzed epimerization of the benzyl 7 beta-(p-nitrobenzylideneimino)desacetoxycephalosporanate and of the S-sulfoxide of natural methyl 6-phenylacetamidodesacetoxycephalosporanate. In both reactions 1,5-diazabicyclo(4.3.0)non-5-ene (DBN) was used as epimerization catalyst.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cephalosporins
Language:
En
Journal:
J Antibiot (Tokyo)
Year:
1979
Document type:
Article