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Liquid phase synthesis of methylene lactones using novel catalyst
申请人:Hutchenson W. Keith
公开号:US20060025610A1
公开(公告)日:2006-02-02
Process for converting certain lactones to their alpha-methylene derivatives in the liquid phase with both high conversion and selectivity using easily recoverable novel heterogeneous catalysts.
Supercritical fluid phase synthesis of methylene lactones using novel catalyst field of invention
申请人:Hutchenson W. Keith
公开号:US20060025608A1
公开(公告)日:2006-02-02
Process for converting certain lactones to their alpha-methylene substituted forms that not only exhibits high initial activity (conversion), but also provides high reactor productivity (mass of product per mass of catalyst per unit of time) and sustained maintenance of a high level of activity and productivity with time on stream.
The N-heterocycliccarbene (NHC)-catalyzed dimerizations of a variety of disubstituted Michael acceptors have been investigated. In addition to the tail-to-tail dimerization of methacrylates reported previously, the scope of vinylidene substrates expands to γ-methyl-α-methylene-γ-butyrolactone, dimethyl 2-methylenepentanedioate, dimethyl itaconate, methacrylamides, and 2-isopropenylbenzoxazole, none
Total syntheses of both enantiomers of amphirionin 4: A chemoenzymatic based strategy for functionalized tetrahydrofurans
作者:Arun K. Ghosh、Prasanth R. Nyalapatla
DOI:10.1016/j.tet.2017.02.031
日期:2017.4
The total syntheses of (-)-amphirionin-4 and (+)-amphirionin-4 have been achieved in a convergent and enantioselective manner. The tetrahydrofuranol cores of amphirionin-4 were constructed in optically active form by enzymatic resolution of racemic cis-3-hydroxy-5-methyldihydrofuran-2(3H)-one. The polyene side chain was efficiently synthesized using Stille coupling. The remote C8-stereocenter was constructed
A new stereospecific route to α-alkylidene γ-lactones
作者:W. Roy Jackson、Patrick Perlmutter、Andrew J. Smallridge
DOI:10.1039/c39850001509
日期:——
Hydrocyanation of a range of protected β-hydroxyalkynes give unsaturated nitriles which can be cyclised to α-alkylideneγ-lactones and in most cases the regioselectivity of hydrocyanation can be controlled giving the desired cyanoalkenes with stereospecific formation of the E-isomer.