Action du chloroallyllithium sur les aldehydes et les cetones: synthese en une etape d'alcools β-ethyleniques γ-chlores de configuration z et d'epoxydes α-ethyleniques bi- ou tri-substitues
作者:A. Doucoure、B. Mauze、L. Miginiac
DOI:10.1016/s0022-328x(00)87068-0
日期:1982.9
Chloroallyllithium readily reacts with aliphatic and aromatic aldehydes and ketones to produce, in a one-step reaction, Z-γ-chlorinated-β-ethylenic alcohols and bi- or tri-substituted epoxides.
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.