| abstract |
Compounds of the formula: <IMAGE> in which A is a thio or sulphinyl group, R<1> is hydrogen or acyl and R<2> is the radical of various thiols, thioamides etc., and their salts and esters are prepared by reacting a corresponding 3-halomethyl or 3-lower-alkanoyloxymethyl compound or a salt or ester thereof with a compound R<2>H in the presence of a quaternary ammonium salt or of a phosphonium salt. If desired, the sulphinyl compounds can be reduced to thio compounds, or a carboxyl group which is protected as a salt or as an ester can be unblocked. The compounds have antibacterial activity. |