HALOSUBSTITUTED 1,4-OXATHIOCINES. PREPARATION FROM THIOPHENE S,C-YLIDES AND STUDIES OF THERMAL REACTIVITY

Abstract

The reaction between tri- and tetrasubstituted thiophenes and diazocarbonyl compounds gave in most cases the corresponding 1,4-oxathiocines directly, without isolation of the intermediate C-S ylides. Two oxathiocines underwent thermal fragmentation leading to sulfur extrusion and the formation of tetra-substituted phenols. A mechanism for the fragmentation is proposed and discussed.

Key Words:

• Thiophene-S,C-ylides
• oxathiocines
• thermal fragmentation