Helical Twisting Power of Optically Active Spiro Compounds with a 3,3′-(4H,4′H)-Spirobi(2H-naphtho[1,2-b]pyran) Skeleton

2008 ◽  
Vol 37 (11) ◽  
pp. 1124-1125 ◽  
Author(s):  
Kenta Tojo ◽  
Tatsuya Arisawa ◽  
Yoshio Aoki ◽  
Daiyo Terunuma
Keyword(s):  
Spiro Compounds ◽  
Optically Active ◽  
Helical Twisting Power

Relationship between Chemical Structure and Helical Twisting Power in Optically Active Imine Dopants Derived from (R)-(+)-1-(1-Naphthyl)ethylamine

2007 ◽  
Vol 46 (8A) ◽  
pp. 5208-5212 ◽  
Author(s):  
Kaoru Fukuda ◽  
Hideyuki Suzuki ◽  
Jin Ni ◽  
Masatoshi Tokita ◽  
Junji Watanabe
Keyword(s):  
Chemical Structure ◽  
Optically Active ◽  
Helical Twisting Power

Synthesis of optically active 2-amino-1′-benzyl-2′,5-dioxo-5H-spiro[indeno[1,2-b]pyran-4,3′-indoline]-3-carbonitriles catalyzed by a bifunctional squaramide derived from quinine

2021 ◽  
Vol 45 (5) ◽  
pp. 2609-2613
Author(s):  
Yuanyuan Wang ◽  
Zhonglin Wei ◽  
Jungang Cao ◽  
Dapeng Liang ◽  
Yingjie Lin ◽  
...  
Keyword(s):  
Spiro Compounds ◽  
Optically Active ◽  
Asymmetric Reaction

The first organocatalytic asymmetric reaction of propylene malononitrile with oxoindole and 1,3-indandione for the synthesis of chiral indeno-spiro compounds has been developed.

Optical analysis of ink and other contaminants in process waters

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI
Keyword(s):  
Optically Active ◽  
Process Water ◽  
Paper Machine ◽  
Optical Analysis ◽  
Direct Process ◽  
Active Components ◽  
Water Contaminants ◽  
Dependent Measurement ◽  
Measurement Methodology

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.

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