Production of 2,5-Dihydrofurans and Analogous Compounds
申请人:Njardarson Jon
公开号:US20090131691A1
公开(公告)日:2009-05-21
Vinyl oxiranes are rearranged to 2,5-dihydrofuran using catalyst (III) or (IV). The 2,5-dihydrofuran can be reduced to tetrahydrofuran. 3,4-Epoxy-1-butene substrate is converted to 2,5-dihydrofuran which in turn is converted to tetrahydrofuran. Substrate for making 3-methyltetrahydrofuran is prepared from isoprene. Substrate for making 2-methyltetrahydrofuran is prepared from piperylene. Reactions analogous to that with vinyl oxiranes are carried out with vinyl thiiranes and vinyl aziridines.
作者:Lindsay A. Batory、Christine E. McInnis、Jon T. Njardarson
DOI:10.1021/ja067073o
日期:2006.12.1
A novel copper-catalyzed vinyl oxirane ring expansion protocol has been developed. A wide range of vinyl oxiranes can be rearranged to 2,5-dihydrofurans in excellent yields in the presence of electrophilic copper(II) acetylacetonate catalysts. Regioisomeric vinyl oxiranes can be converted to a single dihydrofuran product using these conditions. This method uses low catalyst loadings (0.5-5 mol %), has good tolerance of substitution patterns, and can be done in the absence of solvent.