Ruthenium-Catalyzed Hydrohydroxyalkylation of Acrylates with Diols and α-Hydroxycarbonyl Compounds To Form Spiro- and α-Methylene-γ-butyrolactones

摘要: Under the conditions of ruthenium(0)-catalyzed hydrohydroxyalkylation, vicinal diols 1a–1l and methyl acrylate 2a are converted to corresponding lactones 3a–3l in good excellent yield. The reactions with hydrobenzoin 1f, benzoin didehydro-1f, benzil tetradehydro-1f form same lactone 3f product, demonstrating that this process may be deployed a redox level-independent manner. A variety substituted acrylic esters 2a–2h participate spirolactone formation, as illustrated conversion N-benzyl-3-hydroxyoxindole 1o cycloadducts 4a–4h. Hydrohydroxyalkylation hydroxyl-substituted methacrylate 2i 1b, 1j, 1l forms α-exo-methylene-γ-butyrolactones 5b, 5f, 5j, 5l moderate catalytic cycle involving 1,2-dicarbonyl–acrylate oxidative coupling oxaruthenacyclic intermediates is postulated. catalytically competent mononuclear ruthenium(II) complex was characterized by single-crystal X-ray diffraction. influe...