Dermatofibrosarcoma protuberans coexisting with sarcoid reaction in a patient with sarcoidosis

The furan framework is ubiquitous in naturally occurring compounds, and furan-containing structures are also key intermediates to many industrially important chemicals and materials. There have been reports of numerous methods to synthesise furans, however most of them use transition metal catalysts or Br & oslash;nsted acid catalysts under harsh conditions. This work describes the development of a new non-metal Br & oslash;nsted acid catalytic method for the synthesis of 2-aryl-3-carboxylate ester furans and 2,3-diaryl furans from ynone substrates. The method was shown to be efficient under very mild reaction conditions with up to 94% product yields.