Synthesis of o-dimethylene isoxazole via isoxazole-fused 3-sulfolene

Article abstract of DOI:10.1016/S0040-4039(00)74736-8

Isoxazole-fused 3-sulfolene 12 has been synthesized from the readily available starting material 7 in three steps. Heating compound 12 at 160-180°C generates o-dimethylene isoxazole 6b which undergoes smooth cycloaddition reactions.