Optically active allylsilanes. II. Stereochemistry in electrophilic substitution (SE') reactions of optically active allylfluorosilanes

1987 ◽  
Vol 6 (4) ◽  
pp. 884-885 ◽  
Author(s):  
Tamio. Hayashi ◽  
Yonetatsu. Matsumoto ◽  
Yoshihiko. Ito
Keyword(s):  
Electrophilic Substitution ◽  
Optically Active

The Chemistry of Metal Chelate Rings. IV. Electrophilic Substitution of Optically Active Tris-acetylacetonates

1963 ◽  
Vol 2 (3) ◽  
pp. 576-580 ◽  
Author(s):  
James P. Collman ◽  
Robert P. Blair ◽  
Roger L. Marshall ◽  
Laird Slade
Keyword(s):  
Electrophilic Substitution ◽  
Metal Chelate ◽  
Optically Active ◽  
Chelate Rings

Carvone- and Piperitone-Derived Allylic Stannanes and Aspects of Their Electrophilic Substitution

1986 ◽  
Vol 39 (4) ◽  
pp. 563 ◽  
Author(s):  
D Young ◽  
M Jones ◽  
W Kitching
Keyword(s):  
Sulfur Dioxide ◽  
Electrophilic Substitution ◽  
Optically Active ◽  
Substitution Reactions ◽  
Cis And Trans

cis - and trans- Carvotanacetols and - piperitols have been converted into the corresponding allylic chlorides, which were made to react with both trimethyltinlithium and triphenyltinlithium . The resulting allylic stannanes were characterized by 1H, 13C and 119Sn n.m.r . spectroscopy, which permitted assignment of the relative configurations. Triphenyltinlithium appears to react in a (substantially) concerted fashion with the (optically active) chloride from the carvotanacetols yielding an optically active stannane . The corresponding trimethylstannane is optically inactive. Substitution reactions (SE′) with acid and sulfur dioxide (in chloroform) are preferentially γ-anti and specifically γ- syn respectively, in line with conclusions based on other cyclohex-2-enyl systems.

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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