An Efficient Prins Cyclization for Stereoselective Synthesis of Tetrahydropyran from Imines and Homoallyl Alcohols
作者:Congrong Liu、Daojuan Cheng、Fulai Yang
DOI:10.1002/cjoc.201400450
日期:2014.11
An unprecedented protocol has been developed for the efficientsynthesis of substituted tetrahydropyrans via a bismuth‐promoted Prinscyclization of imines with homoallylalcohols. In the presence of 40 mol% BiCl3, a wide variety of imines react smoothly with homoallylalcohols at room temperature to give the corresponding 4‐chlorotetrahydropyran derivatives in good to excellent yields.
Prins cyclization between a homoallylic alcohol and an aldehyde, promoted by trimethylsilyl halide, afforded 4-halo-tetrahydropyrans with good to excellent yields. Thanks to the absence of the solvent and metal, the THP thus obtained have been implicated without purification in several other reactions, in a sequential way, affording in particular new indole derivatives.
Iron(III)-Catalyzed Prins-Type Cyclization Using Homopropargylic Alcohol: A Method for the Synthesis of 2-Alkyl-4-halo-5,6-dihydro-2<i>H</i>-pyrans
作者:Pedro O. Miranda、David D. Díaz、Juan I. Padrón、Jaime Bermejo、Victor S. Martín
DOI:10.1021/ol034568z
日期:2003.5.1
new Prins-type cyclization between homopropargylic alcohol and aldehydes in the presence of FeX(3) to obtain 2-alkyl-4-halo-5,6-dihydro-2H-pyrans in good yield is described. Osmium-catalyzed cis dihydroxylation provided direct access to trans-2-alkyl-3-hydroxy-tetrahydro-pyran-4-ones. Anhydrous ferric halides are also shown to be excellent catalysts for the standard Prins cyclization using homoallylic
One-pot synthesis and SAR study of cis-2,6-dialkyl-4-chloro-tetrahydropyrans
作者:Pedro O. Miranda、Leticia G. León、Víctor S. Martín、Juan I. Padrón、José M. Padrón
DOI:10.1016/j.bmcl.2006.03.064
日期:2006.6
A series of cis-2,6-dialkyl-4-chloro-tetrahydropyrans were prepared by means of an iron(III)-catalyzed process. The in vitro antiproliferative activities were examined in the human solid tumor cell lines A2780, SW1573, and WiDr. The results show that the presence of bulky substituents favors the Prins cyclization leading to new products with better activity profile against all cell lines tested. (c) 2006 Elsevier Ltd. All rights reserved.