Environmentally benign, one-pot synthesis of pyrans by domino Knoevenagel/6π-electrocyclization in water and application to natural products
作者:Ene Jin Jung、Byung Ho Park、Yong Rok Lee
DOI:10.1039/c0gc00265h
日期:——
In water medium, environmentally benign, facile, and efficient synthesis of pyrans was achieved in good yields by the reactions of a variety of cyclic 1,3-dicarbonyls with several α,β-unsaturated aldehydes. The key strategy was a formal [3+3] cycloaddition by domino Knoevenagel/6Ï- electrocyclization. This methodology was applied to the synthesis of biologically interesting pyranocoumarin, pyranoquinolinone, and pyranonaphthoquinone derivatives along with selected natural and non-natural products.
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.
An efficient synthesis of 2H-chromenones and 2-hydroxyl-2H-chromenones derivatives has been developed from 1,3-dicarbonyls and α,β-unsaturated aldehydes by a controllable regioselective domino cyclization reaction under catalysis of different lipases. 2H-Chromenones derivatives were synthesized by bovine pancreatic lipase (BPL) in acetonitrile, while lipase from Pseudomonas fluorescens (PFL) can catalyze
为2个的有效的合成ħ -chromenones和2-羟基-2- ħ -chromenones衍生物已经从1,3-二羰基和α,β不饱和醛通过在不同脂肪酶催化的可控区域选择性多米诺环化反应的发展。2 H- Chromenones衍生物是由牛胰脂肪酶(BPL)在乙腈中合成的,而荧光假单胞菌(PFL)的脂肪酶则可以在二氯甲烷中以中等至高收率催化2-hydroxyl-2 H -chromenones衍生物的合成。
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.