Brønstedacidscatalyze the addition of enolizable β-diketones, β-ketoesters, and vinylogous amides to α,β-unsaturated aldehydes to lead to substituted chromenones, pyranones, and tetrahydroquinolinones in good yields under mild reaction conditions via a formal [3 + 3] cycloaddition.
Microwave-Assisted Solvent and Catalyst Free Synthesis of 2H-Pyrans
作者:Naushad Edayadulla、Yong Rok Lee
DOI:10.5012/bkcs.2013.34.10.2963
日期:2013.10.20
This paper describes a simple and efficient method involving domino Knovenegal/$6\pi}$ electrocyclization for the preparation of a variety of 2H-pyrans using microwave irradiation under solvent- and catalyst-free conditions. This method offers the advantages of a green approach, high yields, and short reaction times. Sixteen compounds (9a-p) were obtained in good to excellent yields using the procedure.