Penicillin-cephalosporin conversion. VII. An improved synthesis of 3-methylenecephams

S. Torii, H. Tanaka, T. Siroi

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Efficient conversion of 2-(7-oxo-2,6-diaza-4-thiabicyclo left bracket 3. 2. 0 right bracket hept-2-en-6-yl)-3-chloromethyl-3-butenoates (4), derived from natural pencillins, into 3-methylenecephams (1) has been performed by a simple two-step operation, which comprises replacement of the allylic chlorine atom of 4 with iodine and subsequent acid-catalyzed hydrolysis, leading to 1 in 70-54% overall yields. In the latter step, the ring opening of the thiazoline moiety and the intramolecular substitution of the iodide with the thiol group proceed simultaneously.

Original languageEnglish
Pages (from-to)1567-1568
Number of pages2
JournalBulletin of the Chemical Society of Japan
Issue number5
Publication statusPublished - 1983
Externally publishedYes

ASJC Scopus subject areas

  • General Chemistry


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