Solvent-free synthesis of functionalized 5-imino-2,5-dihydrofurans from isocyanides, activated acetylenes and alkyl cyanoformates
The reaction between alkyl(aryl) isocyanides, dialkyl acetylenedicarboxylates and alkyl cyanoformates under solvent-free conditions leads to dialkyl 2-cyano-5-alkyl(aryl)imino-2-alkoxy-2,5-dihydrofuran-3,4-dicarboxylates in high yields.
We have used IR spectroscopy to study the reaction between L-cysteine and dimethyl sulfoxide in aqueous medium. We have found that reaction occurs with formation of an insoluble product, which we have identified. We show that oxidation of L-cysteine by dimethyl sulfoxide can occur at an appreciable rate under mild conditions, with formation of L-cystine, dimethyl sulfide, and water.