A New Simple Procedure for the Isomerization of 2-Furylcarbinols to Cyclopentenones
摘要:
The previously reported acid catalyzed isomerization of 2-furylcarbinols to 5-alkyl-4-hydroxycyclopent-2-enones was performed in boiling water in the absence of any acid catalyst. In this case the reaction led to the formation of more stable isomer 2-alkyl- or 2-aryl-4-hydroxycyclopent-2-enones. The reaction of chiral 2-furylcarbinol in the presence of zinc chloride gave a racemic cyclopentenone while 2-furylcarbinol did not undergo racemization. A new mechanism for the conversion of 2-furylcarbinols into cyclopentenone is proposed.
A highly efficient one‐pot transformation of readily accessible furans into 4‐hydroxy‐2‐cyclopentenones in H2O, using singlet oxygen as oxidant, has been developed.