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201.
Patrick Achenbach Carlos Ayerbe Gayoso Ralph Böhm Olga Borodina Damir Bosnar Vakkas Bozkurt Luka Debenjak Michael O. Distler Anselm Esser Ivica Friščić Yuu Fujii Toshiyuki Gogami Mar Gómez Rodríguez Osamu Hashimoto Satoshi Hirose Hiroki Kanda Masashi Kaneta Eunhee Kim Junichiro Kusaka Amur Margaryan Harald Merkel Ulrich Müller Sho Nagao Satoshi N. Nakamura Josef Pochodzalla Christophe Rappold Joerg Reinhold Takehiko R. Saito Alicia Sanchez Lorente Salvador Sánchez Majos B. Sören Schlimme Matthias Schoth Florian Schulz Concettina Sfienti Simon Širca Liguang Tang Michaela Thiel Kyo Tsukada 《Few-Body Systems》2014,55(8-10):887-892
At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak decays (MWD) of electroproduced Λ-hypernuclei were performed. A unique setup was realized to use the broad momentum-band kaon spectrometer Kaos at zero degree angle with respect to the high-intensity electron beam direction to tag strangeness producing processes. A sample of order 103 MWD from a beryllium target was collected by the coincidence technique with the high-resolution multi-spectrometer facility of the A1 Collaboration. It is conjectured that this sample contains monochromatic two-body decays from stopped hyperfragment decays as well as a wide momentum distribution of quasi-free produced Λ- and Σ-hyperon decays and three-body decays from hyperfragments. Stopped hyperfragments will be identified as monochromatic peaks in the π ? momentum spectrum from which their masses can be extracted with a precision of 50 keV/c 2. 相似文献
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Anna Żądło-Dobrowolska Joerg H. Schrittwieser Barbara Grischek Dominik Koszelewski Wolfgang Kroutil Ryszard Ostaszewski 《Tetrahedron: Asymmetry》2017,28(6):797-802
A biocatalytic approach was employed for the asymmetric reduction of sterically demanding ketones to prepare 3-hydroxy-5-oxo-5-phenylpentanoates and 5-hydroxy-3-oxo-5-phenylpentanoates. Screening a collection of microorganisms led to the identification of stereocomplementary microbial strains that provide access to both enantiomers of 3-hydroxy-5-oxo-5-phenylpentanoates and 5-hydroxy-3-oxo-5-phenylpentanoates with high enantiomeric excess (up to 99% ee). Moreover, the application of Saccharomyces cerevisiae gave two diastereomers of 3,5-dihydroxy-5-phenylpentanoates with high enantiomeric excess (up to 99% ee). The applicability of the identified strains was demonstrated by transforming the obtained dihydroxy ester into the chemically valuable lactone (4S,6R)-tetrahydro-4-hydroxy-6-phenyl-pyran-2-one. 相似文献
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