6053-54-9Relevant academic research and scientific papers
Ruthenium-catalyzed hydrohydroxyalkylation of acrylates with diols and α-hydroxycarbonyl compounds to form spiro- and α-methylene-γ- butyrolactones
McInturff, Emma L.,Mowat, Jeffrey,Waldeck, Andrew R.,Krische, Michael J.
supporting information, p. 17230 - 17235 (2013/12/04)
Under the conditions of ruthenium(0)-catalyzed hydrohydroxyalkylation, vicinal diols 1a-1l and methyl acrylate 2a are converted to the corresponding lactones 3a-3l in good to excellent yield. The reactions of methyl acrylate 2a with hydrobenzoin 1f, benzoin didehydro-1f, and benzil tetradehydro-1f form the same lactone 3f product, demonstrating that this process may be deployed in a redox level-independent manner. A variety of substituted acrylic esters 2a-2h participate in spirolactone formation, as illustrated in the conversion of N-benzyl-3-hydroxyoxindole 1o to cycloadducts 4a-4h. Hydrohydroxyalkylation of hydroxyl-substituted methacrylate 2i with diols 1b, 1f, 1j, and 1l forms α-exo-methylene-γ-butyrolactones 5b, 5f, 5j, and 5l in moderate to good yield. A catalytic cycle involving 1,2-dicarbonyl-acrylate oxidative coupling to form oxaruthenacyclic intermediates is postulated. A catalytically competent mononuclear ruthenium(II) complex was characterized by single-crystal X-ray diffraction. The influence of electronic effects on regioselectivity in reactions of nonsymmetric diols was probed using para-substituted 1-phenyl-1,2-propanediols 1g, 1m, and 1n and density functional theory calculations.
Diverting non-haem iron catalysed aliphatic C-H hydroxylations towards desaturations
Bigi, Marinus A.,Reed, Sean A.,White, M. Christina
scheme or table, p. 216 - 222 (2011/12/16)
Carboxylate-ligated, non-haem iron enzymes demonstrate the capacity for catalysing such remarkable processes as hydroxylations, chlorinations and desaturations of inert, aliphatic C-H bonds. A key to functional diversity is the enzymes' ability to divert fleeting radicals towards different types of functionalization using active site and/or substrate modifications. We report that a non-haem iron hydroxylase catalyst [Fe(PDP)] can also be diverted to catalytic, mixed hydroxylase/desaturase activity with aliphatic C-H bonds. Using a taxane-based radical trap that rearranges under Fe(PDP) oxidation to furnish a nortaxane skeleton, we provide the first direct evidence for a substrate radical using this class of stereoretentive hydroxylation catalysts. Hydroxylation and desaturation proceed by means of a short-lived radical that diverges in a substrate-dependent manner in the presence of carboxylic acids. The novel biomimetic reactivity displayed by this small molecule catalyst is harnessed to diversify natural product derivatives as well as interrogate their biosynthetic pathways.
Studies toward the Syntheses of Functionally Substituted γ-Butyrolactones and Spiro-γ-butyrolactones and Their Reaction with Strong Acids: A Novel Route to α-Pyrones
Mandal, A.K.,Jawalkar, D.G.
, p. 2364 - 2369 (2007/10/02)
A general strategy for the conversion of 5-keto carboxylic acids, 6 (via their enol-lactones 7), to a variety of γ-lactones, 8a-c, and spiro-γ-lactones, 8d-g, is described.Lactones 8b and 8d,e may be further converted into the corresponding α-pyrones, 17b and 17d,e, respectively, in the presence of strong acids.
A VERSATILE AND CONCISE ROUTE TO FUNCTIONALLY SUBSTITUTED γ-BUTYROLACTONES AND SPIRO-γ-BUTIROLACTONES (LACTONE ANNELATION)
Mandal, Arun K.,Jawalkar, D. G.
, p. 99 - 100 (2007/10/02)
A novel route to the synthesis of functionally substituted γ-butyrolactones and spiro-γ-butyrolactones, from six-membered cyclic enol-esters, is described.
