β-phenylsulfonylenones as α,β-acetylenic ketones equivalents in diels-alder reactions
作者:Fernando M. Leon、Juan C. Carretero
DOI:10.1016/s0040-4039(00)92398-0
日期:1991.9
(E)-beta-phenylsulfonylenones, readily prepared by oxidation of the alcohols, react with a wide variety of dienes in the presence of activated silica gel. The basic elimination of the phenylsulfonyl group in the resulting adducts gives high yields of the corresponding enones, thus showing the usefulness of these dienophiles as reactive synthetic equivalents of alpha,beta-acetylenic ketones.
An efficient preparation of optically active (E)-γ-hydroxy-α,β-unsaturated phenyl sulfones using lipase-mediated acylations
作者:Esteban Domínguez、Juan Carlos Carretero、Alfonso Fernández-Mayoralas、Santiago Conde
DOI:10.1016/s0040-4039(00)93455-5
日期:1991.9
(E)-gamma-Hydroxy-alpha,beta-unsaturated phenyl sulfones have been efficiently resolved via irreversible enzymatic acylation with lipase PS (pseudomonas cepacia) and vinyl acetate. This process has been applied to the synthesis of the aggregation pheromone (-)-(3S,4S)-4-methyl-3-heptanol.
Asymmetric Synthesis of Cycloalkenyl and Alkenyloxiranes From Allylic Sulfoximines and Aldehydes and Application to Solid-Phase Synthesis
作者:Hans-Joachim Gais、Gadamsetti S. Babu、Markus Günter、Parthasarathi Das
DOI:10.1002/ejoc.200300726
日期:2004.4
chlorohydrins gave the corresponding enantio- and diastereomericallypure cis-configured cycloalkenyloxiranes in good overall yields, the alkenyl chlorohydrins afforded mixtures of enantiomerically pure trans and cis isomers in which the trans isomers dominated. The solution-phase synthesis was extended to the solid phase by the synthesis of an enantiomerically pure, polymer-bound allylic sulfoximine and its
Synthesis and conjugate additions to (E)-γ-alkoxy-α-substituted-α,β-unsaturated sulfones
作者:Carmen Alcaraz、Juan C. Carretero、Esteban Domínguez
DOI:10.1016/s0040-4039(00)79674-2
日期:1991.3
(E)-gamma-hydroxy-alpha,beta-unsaturated sulfones have been readily functionalized at alpha-position via protection of hydroxyl group, metalation with n-BuLi and subsequent reaction with electrophiles. The conjugate addition of organolithiums to (E)-gamma-methoxymethoxy-alpha-trimethylsilyl-alpha, beta-unsaturated phenyl sulfones in Et2O is highly syn-stereoselective.
Stereoselective synthesis of substituted γ-butyrolactones from γ-hydroxy-α,β-unsaturated phenyl sulfones
作者:Javier Rojo、Mercedes García、Juan C Carretero
DOI:10.1016/s0040-4020(01)80181-2
日期:1993.1
α-(phenylsulfonyl)-α,β-unsaturated esters 3 or α-(phenylsulfonyl)butenolides 4 is described. This method is based on the conjugateaddition of organoaluminum reagents (Me3Al, Et3Al and Et2AlCN) to substrates 3 and 4. Whereas the conjugateaddition to Michael acceptors 3 occurs with complete syn-selectivity, the conjugateaddition to butenolides 4 is usually anti-selective. This methodology has been applied