摘要:
2,5-Dihydrothiophene 5,5-dioxides 8 and 6 have been obtained by interception of flash-pyrolytically produced 2,3-dihydro-2,3-bis(methylene)thiophene with sulfur dioxide and from methyl 4,5-bischloromethylthiophene-2-carboxylate by reaction with sodium sulfide and oxidation. Pyrazole fused analogues 15 and 16 (R = Me and COPh) were prepared from 3-phenylsulfonyl-2,5-dihydrothiophene S,S-dioxide by cycloaddition