Mild conversion of propargylic alcohols to α,β-unsaturated enones in ionic liquids (ILs); a new ‘metal free’ life for the Rupe rearrangement
作者:Ganesh C. Nandi、Benjamin M. Rathman、Kenneth K. Laali
DOI:10.1016/j.tetlet.2013.09.028
日期:2013.11
free protocol for the conversion of propargylic alcohols to cyclic and acyclic α,β-unsaturated enones via the Rupe rearrangement is reported. The method utilizes the Brønsted acidic ionic liquid [BMIM-SO3H][OTf] as catalyst and [BMIM][PF6] as solvent and offers the potential for recycling and reuse of the IL solvent. The feasibility to synthesize bicyclic fused cyclopentenone derivatives via a Rupe → Aldol → Nazarov
A Novel Synthesis of Methylenecyclopropane Spiro-Linked with Cycloalkanes via a Cyclization of Allylic Epoxides and Its Application to a Synthesis of Fused 3-Methylfurans
作者:Tsuyoshi Satoh、Yasushi Kawase、Koji Yamakawa
DOI:10.1246/bcsj.64.1129
日期:1991.4
Ring closure of allylicepoxides derived from 1-chloroalkyl phenyl sulfoxides and cyclic ketones with lithium diisopropylamide (LDA) in 3-Exo-Tet mode gave spiro-linked methylenecyclopropanes having a hydroxyl group in good yields. Oxidation of these compounds gave ketones, which were then treated with p-toluenesulfonic acid in 1,4-dioxane or DMSO at 100°C to give fused 3-methylfurans in good overall
A new synthesis of α,β-unsaturated ketones. Allylic alkylation of 1-isocyano-1-tosylalkenes
作者:Jarusz Moskal、Albert M van Leusen
DOI:10.1016/s0040-4039(01)81237-5
日期:1984.1
Ketone (1) are homologated to enones 2 by alkylating (introduction of R3) the condensation products 4 (derived from 1 and tosylmethyl isocyanide), followed by acid catalyzed hydrolysis.
Nazarov cyclization of divinyl ketones bearing an ester group at the β-position: a remarkable effect of α-substitution and alkene geometry on regioselectivity
these observations are an aromatic group at the α-position with E-olefin geometry provides a cyclopentenone in which the double bond is not in conjugation with an ester, whereas Z-olefin provides a cyclopentenone in which the double bond is in conjugation with an ester; and divinyl ketones bearing an ester group at the β-position and an alkyl group at the α-position with E-olefin geometry provide a cyclopentenone
Cerium(III) chloride remarkably increases the rates of formation and yields of ketones in the reaction of lithium carboxylates with organolithiums
作者:Yoonmo Ahn、Theodore Cohen
DOI:10.1016/s0040-4039(00)76511-7
日期:1994.1
ketones in the reaction of organolithiums with lithiumcarboxylates. The CeIII suppresses the enolization of the lithiumcarboxylate, previously unrecognized as a competing reaction except in special cases, and the formation of tertiary alcohols. One of the reasons for the latter effect is a surprising increase in the rate of addition of the organometallic to the lithiumcarboxylate in the presence