摘要 |
<p>There is disclosed a process for preparing a penicillin or cephalosporin sulfone of the formula …<CHEM>… wherein:… R<1> is hydrogen or a carboxylic acid acyl residue;… R<2> is hydrogen or lower alkoxy;… R<3> is hydrogen, a carboxy protecting group or a salt forming group;… A is …<CHEM>… in which:… R<4> is halo, lower alkyl, lower alkoxy, or -CH2R<6>, wherein R<6> is lower alkanoyloxy or a heterocyclic group; and… R<5> is hydrogen or alkoxycarbonyloxy; comprising reacting a compound of the formula …<CHEM>… with an oxidizing agent and a catalytic amount of ruthenium tetroxide.</p> |