Conversion of cepham-1-oxide into 1-oxadethiacepham

✍ Scribed by Hiroaki Yanagisawa; Akiko Ando

• Book ID: 104221065
• Publisher: Elsevier Science
• Year: 1982
• Tongue: French
• Weight: 264 KB
• Volume: 23
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)87620-0

✦ Synopsis

Hiromachi l-2-58, Shinagawa-ku, Tokyo, 140, Japan Summary 3-Exomethylenecepham-l-oxides 1 were converted into the 3-exomethylenel-oxadethiacepham in three step process including the novel bond cleavage of the tetrahydrothiazine ring of 1 with 2-mercaptobenzothiazole or 2-mercaptobenzoxazole.

Since the antibacterial activity of the racemlc l-oxadethiacephalosporinl was reported, much effort2 has been expanded to make one of the optically active constituents from penicillin and cephalosporin.

Recently the industrially practical procedure 2e ¶f for producing l-oxadethiacephalosporin from penicillin was announced and the new clinically useful B-lactam antibiotic3 was developed.

We wish to describe here simple transformation of cepham-l-oxides la, lb into the 1-oxadethiacepham l by the use of the novel ring opening reactions of la and lb with the mercaptans &, z.

-Treatment of the cepham-ld-oxide la and la-oxide lb4 with 2a (1.9 eq.) in --benzene under reflux gave the crystalline disulfide-alcohol 3a5 in 38% and 42% yields, respectively.

Similarly the reaction of la with 2b afforded 3b5 in 43% --