摘要:
The invention is concerned with the preparation of .DELTA..sup.3 -4-carboxy cephalosporin antibiotics possessing a 3-vinyl group or substituted 3-vinyl group by means of phosphorous intermediates.
摘要:
Novel semisynthetic .beta.-lactam intermediates of use in the production of cephalosporins, penicillins and related .beta.-lactam antibiotic compounds are provided. The novel compounds are prepared from .beta.-lactams obtained by cleavage of the 1,2-sulphur-carbon bond of a penicillin 1-oxide (with subsequent internal or external trapping of the sulphur atom to leave a residual substituent as the .beta.-lactam nitrogen) by removal of the said residual substituent by an oxidative cleavage reaction.