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
A New Catalytic Prins Cyclization Leading to Oxa- and Azacycles
作者:Pedro O. Miranda、Rubén M. Carballo、Víctor S. Martín、Juan I. Padrón
DOI:10.1021/ol802593u
日期:2009.1.15
A new Prins cyclization process that builds up one carbon−carbon bond, one heteroatom-carbon bond, and one halogen-carbon bond, (in an oxa- and azacycle) relies on an iron catalyst system formed from Fe(acac)3 and trimethylsilyl halide. The method displays a broad substrate scope and is economical, environmentally friendly, and experimentally simple. This catalytic method permits the construction of