13C NMR spectroscopic studies of the behaviors of carbonyl compounds in various solutions
作者:Yoshikazu Hiraga、Saori Chaki、Satomi Niwayama
DOI:10.1016/j.tetlet.2017.10.071
日期:2017.12
13C NMRspectroscopicstudies were performed for carbonyl compounds having a hydroxyl group, a carboalkoxy group, an acetoxy group, or a carboxyl group in various solvents with different polarities for observation of their behaviors of 13C NMR chemical shifts of carbonyl carbons in solutions. It was found that the chemical shifts of the carbonyl carbons in 13C NMR have good correlation with the empirical
在具有不同极性的各种溶剂中,对具有羟基,碳烷氧基,乙酰氧基或羧基的羰基化合物进行13 C NMR光谱研究,以观察其在溶液中的羰基碳的13 C NMR化学位移行为。发现在13 C NMR中羰基碳的化学位移与溶剂极性的经验参数E T N取决于结构,具有很好的相关性。分子间或分子内氢键和偶极-偶极相互作用似乎在这一观察中起关键作用。
Exploration of Thermophilic Esterases/Lipases for Asymmetric Desymmetrization of Norbornane Derivatives
Asymmetric monohydrolysis of a series of norbornanederivatives by a thermophilic esterase/lipase library was examined. Three esterases/lipases showed high enantioselectivities toward dialkyl bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylates with high chemical yields.
A thermophilic enzyme efficiently monohydrolyzed a series of meso diesters, dialkyl bicycle[2.2.1]hept-2,5-diene-2,3-dicarboxylates, in high chemical yields (72-98%) and high enantiomeric purities (>99% e.e.) in all the cases examined. (C) 2002 Elsevier Science Ltd. All rights reserved.
Asymmetric synthesis of 6-formyl-1-alkoxycarbonylbicyclo[3.1.0]hex-2-ene-2-carboxylic acids by a novel buffer-mediated rearrangement
作者:Satomi Niwayama、Jianxiu Liu
DOI:10.1016/s0957-4166(01)00430-x
日期:2001.10
Asymmetric synthesis of 6-formyl-1-alkoxycarbonylbicyclo[3.1.0]hex-2-ene-2-carboxylic acids has been achieved and the absolute configurations of the products of a novel buffer-mediated rearrangement have been established. (C) 2001 Elsevier Science Ltd. All rights reserved.
ARAI, YOSHITSUGU;HAYASHI, KAZUYA;KOIZUMI, TORU;SHIRO, MOTOO;KURIYAMA, KAO+, TETRAHEDRON LETT., 29,(1988) N 47, C. 6143-6146