156418-97-2Relevant articles and documents
Enantioselective hydrolysis of functionalized 2,2-disubstituted oxiranes with bacterial epoxide hydrolases
Steinreiber, Andreas,Osprian, Ingrid,Mayer, Sandra F.,Orru, Romano V. A.,Faber, Kurt
, p. 3703 - 3711 (2007/10/03)
The biohydrolysis of 2,2-disubstituted oxiranes bearing various oxygen functional groups was investigated using the epoxide hydrolase activity of 11 bacterial strains. The results show that the activity and the selectivity strongly depend on the substrate structure and the biocatalyst. Whereas substrates possessing free hydroxyl groups were not transformed, their analogs, protected as ethers, were well accepted. This allowed the convenient modulation of the enantioselectivity by proper choice of the ether group according to size and polarity. It was found that the distance of the ether-oxygen to the stereogenic quaternary carbon center of the oxirane ring had a profound influence on the enantioselectivity, and several oxiranes were resolved with good to excellent selectivities. The enantiomerically enriched epoxides and vicinal diols thus obtained contain a useful 'synthetic handle' in their side chain, which allows their use as building blocks in asymmetric synthesis.
Synthesis of Substituted Cyclooctanols by a Samarium(II) Iodide Promoted 8-Endo Radical Cyclization Process
Molander, Gary A.,McKie, Jeffrey A.
, p. 3186 - 3192 (2007/10/02)
Samarium(II) iodide (SmI2) has been employed to promote an efficient 8-endo radical cyclization reaction of a variety of substituted olefinic ketones.Various substituted monocyclic, fused bicyclic, and bridged bicyclic cyclooctanols have been synthesized in fair to excellent yield via this protocol.In addition to delineating the synthetic potential of this reaction, experiments have been conducted to determine the source of reduced, noncyclized byproducts present in this and related SmI2-mediated reactions performed under protic conditions.
