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.
An enantioselective oxa-Piancatelli reaction was established for the first time using a chiral vanadium(V) catalyst. The dual Brønsted and Lewis acid properties of the vanadium catalyst afforded 4-hydroxycyclopent-2-enone derivatives in up to 90% yields and with 93 : 7 enantiomeric ratios, as well as >20 : 1 diastereomeric ratios.
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.
作者:Matthew B. Plutschack、Peter H. Seeberger、Kerry Gilmore
DOI:10.1021/acs.orglett.6b03237
日期:2017.1.6
method to access highly reactive intermediates from cheap, readily available, and shelf-stable reagents to perform clean chemical transformations. Here, we report the first photoredox-catalyzed Achmatowicz reaction of furfuryl alcohol derivatives to produce functionalized dihydropyranones while only forming easily separable NaHSO4 as a byproduct. The water solubility of the byproduct facilitates direct
作者:Son H. Doan、Mohanad A. Hussein、Thanh Vinh Nguyen
DOI:10.1039/d1cc02947a
日期:——
used to be one of the most powerful synthetic tools to functionalize alcohols and nitriles, providing valuable N-alkyl amide products. However, this reaction has not been frequently used in modern organicsynthesis due to its employment of strongly acidic and harsh reaction conditions, which often lead to complicated side reactions. Herein, we report the development of a new method using salts of the