Stereoconvergent ‘one-pot’ tandem [2,3]-Wittig-anionic oxy-Cope rearrangement of acyclic bis-allylic ethers in the diastereoselective synthesis of substituted tetrahydropyrans
Stereoconvergent ‘one-pot’ tandem [2,3]-Wittig-anionic oxy-Cope rearrangement of acyclic bis-allylic ethers in the diastereoselective synthesis of substituted tetrahydropyrans
Copper-Catalyzed γ-Selective and Stereospecific Allylic Alkylation of Ketene Silyl Acetals
作者:Dong Li、Hirohisa Ohmiya、Masaya Sawamura
DOI:10.1021/ja111645q
日期:2011.4.20
Copper-catalyzed allylic alkylation of ketene silyl acetals proceeded with excellent γ-E-selectivity. Efficient α-to-γ chirality transfer with anti-selectivity occurred in the reaction of enantioenriched secondary allylic phosphates, affording enantioenriched β-branched γ,δ-unsaturated esters. Excellent functional group compatibility was observed.
Convenient in situ generation of various dichlorinating agents from oxone and chloride: diastereoselective dichlorination of allylic and homoallylic alcohol derivatives
作者:Jingyun Ren、Rongbiao Tong
DOI:10.1039/c3ob40670a
日期:——
A safe and convenient protocol was developed for in situ generation of various dichlorinating agents (cf. Cl2, NCl3, Et4NCl3, ArICl2) from oxone and chloride. The synthetic utility of this protocol was demonstrated by diastereoselective dichlorination of a series of allylic and homoallylicalcohol derivatives with excellent yields and diastereoselectivity.
electrocatalytic strategy for the cyclopropanation of activemethylenecompounds, employing an organic catalyst. The method shows a broad substrate scope and excellent scalability, requires no metal catalyst or external chemical oxidant, and provides convenient access to several types of cyclopropane-fused heterocyclic and carbocyclic compounds. Mechanistic investigations suggest that the reactions
Processes for Highly Enantio- and Diastereoselective Synthesis of Acyclic Epoxy Alcohols and Allylic Epoxy Alcohols
申请人:Walsh Patrick
公开号:US20090163728A1
公开(公告)日:2009-06-25
The inventive subject matter relates to novel processes for making an epoxy alcohol from an aldehyde, comprising the steps of: (a) adding (i) an organozinc compound or (ii) divinylzinc compound and an diorganozinc compound to said aldehyde in the presence of a first catalyst to form an allylic alkoxide compound; and (b) epoxidizing said allylic alkoxide compound in the presence of an oxidant and a second catalyst.
An improved Williamson etherification of hindered alcohols promoted by 15-crown-5 and sodium hydride
作者:Helen C. Aspinall、Nicholas Greeves、Wai-Man Lee、Edward G. McIver、Peter M. Smith
DOI:10.1016/s0040-4039(97)00965-9
日期:1997.6
15-crown-5 greatly facilitates Williamson ether synthesis when sodium hydride base is used in THF solvent. This mild yet versatile procedure has been employed in the synthesis of new homochiral polyether ligands and bis-allylic ethers which are inaccessible by conventional methods. (C) 1997 Elsevier Science Ltd.