Takeda Chemical Industries, Inc.

Yoshio Imashiro

Isao Minamida

Mitsuo Numata

Masayoshi Yamaoka

Mitsuru Shiraishi

Shinji Terao

Toshio Miyawaki

Novel compounds of the formula: ##STR1## wherein X is a lower alkanoyloxy group or a substituted thio group, where the substituent is a nitrogen-containing heterocyclic group, or a pharmaceutically acceptable salt or ester thereof, have a broad antimicrobial spectrum, and besides they are readily absorbed into the living body. Thus, the compounds are useful as therapeutic agent for various bacterial infections of animals including human beings.

7-Acetoacetamidocephem compounds

A 3-hydroxymethylcephalosporin which is not protected at the carboxyl group can be directly oxidized with a hexavalent chromium compound to give in good yield a lactol type cephalosporin represented by the general formula: ##SPC1## Wherein R.sup.1 is hydrogen or an alkoxy group and R.sup.2 is an acylamino, or imido group. The resulting compounds are very useful and important as intermediates for preparing, e.g. 3-alkoxyiminomethyl cephalosporins.

Process for producing lactol-type cephalosporins

Growing community of inventors

Nishinomiya, Japan

Yoshio Imashiro