7beta - amino - 3 - cefem - 3 - amino - 4 - karbonsyra - foreningar as intermediate products for framstellning of 7beta - amino - 3 - cefem - 3 - ol - 4 - karbonsyra - foreningar

摘要

The invention concerns a process for the manufacture of 7 beta -amino-3-cephem-3-ol-4-carboxylic acid compounds by ring closure of esters of 2-[4-(substituted-thio)-3-acylamino-2-oxoazetidin-1-yl]-3-substituted- amino-crotonic acids and solvolysing the enamino group in the resulting 7 beta -acylamino-3-substituted-amino-cephem-4-carboxylic acid esters.