NOVEL APPLICATION OF AN ELECTROOXIDATIVE METHOD FOR THE FORMATION OF A TETRAHYDROFURAN RING FROM 5-HYDROXY-2-PENTANONE PHENYLHYDRAZONE

摘要

Various ketone phenylhydrazones that possess a hydroxy group on the parent ketone moiety were subjected to electrooxidation in methanol in the presence of KI and NaOMe. In the case of 4-hydroxy-2-butanone phenylhydrazone, the nucleophilic attack of the azomethine carbon by a methoxide ion affording the corresponding methoxy(phenylazo)alcohol was dominant. Interestingly, however, in the case of 5-hydroxy-2-pentanone phenylhydrazone, similar reaction conditions favored the intramolecular cyclization to afford a (phenylazo)tetrahydrofuran derivative.