Des 6<i>H</i>-thiazines-1,3 aux céphèmes par cyclocondensation

Abstract

The synthesis of new thiazines is described. Their structural determination and their spectroscopic parameters are examined. The [2 + 2] cyclocondensation of these thiazines with ketenes is studied along with the reversibility of the reaction as a function of the nature of the substituents on position 4 and (or) 5 of 6H-1,3-thiazines.