27873-57-0Relevant academic research and scientific papers
Fluorous reverse-phase silica gel-supported Lewis acids as recyclable catalysts in water
Yamazaki, Osamu,Hao, Xiuhua,Yoshida, Akihiro,Nishikido, Joji
, p. 8791 - 8795 (2007/10/03)
Fluorous reverse-phase silica gel (FRPSG)-supported Lewis acids which have fluorous ligands acted as effective catalysts of Baeyer-Villiger and Diels-Alder reactions in water. Direct esterification of carboxylic acid with alcohol in organic media was also catalyzed. The FRPSG-supported Lewis acids could be recycled by simple filtration after the reaction.
OXIDATIVE BISDECARBOXYLATION OF α-ALKOXYMALONIC ACIDS WITH CERIUM(IV)
Salomon, Robert G.,Roy, Subhas,Salomon, Mary F.
, p. 769 - 772 (2007/10/02)
Ceric ammonium nitrate is an excellent reagent for preparing carboxylic esters from α-alkoxymalonic acids by oxidative bisdecarboxylation.
Lactone Formation in Superacidic Media
Carr, Graham,Whittaker, David
, p. 1877 - 1880 (2007/10/02)
The reaction of substituted 1-hydroxycyclohexanecarboxylic acids in fluorosulphuric acid has been studied.Cyclisation takes place around 0 deg C, accompanied by rearrangement in appropriate cases, yielding the thermodynamically stable lactone or mixture of lactones.An unexpected feature of these reactions is that the carboxy-substituted cyclohexyl carbocation does not undergo ring contraction, unlike the unsubstituted cyclohexyl carbocation, although the cycloheptyl system contracts to cyclohexyl.We suggest that the cyclohexyl carbocation is strongly stabilised by carboxyl substitution, as a result of through-space interaction between the carboxyl oxygen atom and the carbocation centre.
ORGANOSELENIUM-INDUCED CYCLIZATIONS IN ORGANIC SYNTHESIS
Nicolaou, K.C.
, p. 4097 - 4109 (2007/10/02)
A number of organoselenium reagents are introduced as efficient initiators of ring closures leading from unsaturated substrates to lactones, cyclic ethers, cyclic thioethers, N-heterocycles and carbocycles.These cyclizations often proceed with high ring selectivity and stereoselectivity and are accompained by the incorporation of the phenylseleno group (PheSe) into the final product.Methods are described for the effective removal of this group (PheSe) by oxidation or reduction achieving unsaturation or saturation.Finally the successful application of this Se-based methodology to the synthesis of stable and biologically active prostacyclins is outlined.Representative experimental procedures are included.
