XLIX.—The action of phosphorus pentachloride on the esters of glyceric acid. Optically active αβ-dichloropropionates

1914 ◽  
Vol 105 (0) ◽  
pp. 456-463 ◽  
Author(s):  
Percy Faraday Frankland ◽  
Andrew Turnbull
1891 ◽  
Vol 59 (0) ◽  
pp. 96-104 ◽  
Author(s):  
Percy F. Frankland ◽  
William Frew

ChemInform ◽  
2010 ◽  
Vol 26 (34) ◽  
pp. no-no
Author(s):  
P. H. J. CARLSEN ◽  
K. MISUND ◽  
J. ROEE

1995 ◽  
Vol 49 ◽  
pp. 297-300 ◽  
Author(s):  
Per H. J. Carlsen ◽  
Kristin Misund ◽  
Johan Røe ◽  
Enrique Colacio ◽  
Harri Lönnberg ◽  
...  

1968 ◽  
Vol 46 (19) ◽  
pp. 3091-3094 ◽  
Author(s):  
C. M. Wong ◽  
J. Buccini ◽  
J. Te Raa

Optically active (−)-deacetyl anisomycin and the enantiomer (+)-deacetyl anisomycin were synthesized starting with (+)-2R 3R tartaric acid. The asymmetric centers of the tartaric acid correspond to the C-2 and C-3 asymmetric centers of anisomycin. N-Benzyl tartarimide (3) was attacked by the Grignard reagent of anisyl chloride followed by lithium aluminium hydride reduction to give two diols (7) and (8) separated by thin-layer chromatography. The diol (8) was debenzylated giving the natural (−)-deacetyl anisomycin. The diol (7) was converted into the epoxide (10) by selective acetylation of the C-4 hydroxy group followed by treatments with phosphorus pentachloride and sodium ethoxide. Opening of the epoxide ring of 10 in boiling acetic acid followed by basic hydrolysis gave (+)-N-benzyl deacetyl anisomycin (11) which was debenzylated to give (+)-deacetyl anisomycin.


Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
M Merlani ◽  
V Barbakadze ◽  
L Gogilashvili ◽  
L Amiranashvili ◽  
K Mulkijanyan ◽  
...  

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.


2003 ◽  
Vol 770 ◽  
Author(s):  
H. Przybylinska ◽  
N. Q. Vinh ◽  
B.A. Andreev ◽  
Z. F. Krasil'nik ◽  
T. Gregorkiewicz

AbstractA successful observation and analysis of the Zeeman effect on the near 1.54 μm photoluminescence spectrum in Er-doped crystalline MBE-grown silicon are reported. A clearly resolved splitting of 5 major spectral components was observed in magnetic fields up to 5.5 T. Based on the analysis of the data the symmetry of the dominant optically active center was conclusively established as orthorhombic I (C2v), with g‼≈18.4 and g⊥≈0 in the ground state. The fact that g⊥≈0 explains why EPR detection of Er-related optically active centers in silicon may be difficult. Preferential generation of a single type of an optically active Er-related center in MBE growth confirmed in this study is essential for photonic applications of Si:Er.


Sign in / Sign up

Export Citation Format

Share Document