P. Marchand et al., SULFUR EXTRUSION REACTION - A VERSATILE CYCLIC BETA-ENAMINO ESTER SYNTHESIS FROM SECONDARY ALPHA-BROMO ESTERS, Synthesis, (11), 1994, pp. 1118-1120
Various commercial secondary alpha-bromo esters 2 react with five-memb
ered thiolactams 1 in a direct sulfur extrusion reaction to give N-alk
ylated tetrasubstituted cyclic beta-enamino esters 4 in good yields.