Diels-Alder Reactions With Unsaturated Sulfoxides. Reactions of (Z)-3-Phenylsulfinylprop-2-Enoic Acid and Methyl-Ester With Furan, 1,3-Diphenylisobenzofuran and Anthracene

1986 ◽  
Vol 39 (4) ◽  
pp. 575 ◽  
Author(s):  
K Picker ◽  
SM Proust ◽  
DD Ridley
Keyword(s):  
Methyl Ester ◽  
High Temperatures ◽  
Low Temperatures ◽  
Diels Alder ◽  
Enoic Acid ◽  
Reaction Conditions ◽  
Thermal Reactions ◽  
Cis And Trans

Methyl (Z)-3-phenylsulfinylprop-2-enoate undergoes Diels -Alder reactions with furan, 1,3-diphenylisobenzofuran and anthracene but chemical and stereochemical courses of the reactions are very dependent upon reaction conditions. Thus, with furan, cis,endo - and cis,exo - adducts are formed exclusively; with 1,3-diphenylisobenzofuran cis,endo - and cis,exo -adducts are formed at low temperatures, whilst the corresponding trans-adducts are formed upon heating; with anthracene where high temperatures are required for condensation cis- and trans-adducts arise together with products from further thermal reactions.

New Thermal and Photochemical Routes to Dewar Furan and Other Isomers on the C4H4O Energy Surface: the Role of Isobenzofuran as a Trapping Agent

1991 ◽  
Vol 44 (9) ◽  
pp. 1275 ◽  
Author(s):  
RN Warrener ◽  
IG Pitt ◽  
RA Russell
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Energy Surface ◽  
Thermal Study ◽  
Diels Alder ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Benzene Oxide ◽  
Trapping Agent

Photolysis of the specially synthesized substrate (39) leads to quantitative fragmentation into the phthalimide (56) and Dewar furan (4a). Dewar furan has only transient existence even at -65°, yet can be trapped effectively with isobenzofuran but not furan. Rapid isomerization to cycloprop-2-enecarbaldehyde (57) occurs at the photolysis temperatures and this product is also trapped by the isobenzofuran . In the absence of trapping agent, photolysis of (39) produces some furan but no 1H n.m.r . evidence can be obtained for (4a) or (57), even at low temperatures (-85°). Separate irradiation of (57) causes extensive polymerization, without yielding other recognizable products. Furan is concluded, therefore, to arise from photoisomerization of (4a) rather than photochemical or thermal isomerization of (57). Separate thermal study of (57) shows that isomerization to furan only occurs above 420°. Flash vacuum pyrolysis of the polycyclic epoxide (72) provides a new retro- Diels-Alder route to (57) which likely proceeds via (4a) as an intermediate. At high temperatures (57) is isomerized to furan. A new Dewar benzene oxide (41) and Dewar benzene (45) are reported en route to the photosubstrates (39) and (50) respectively. Photolysis of (50) provides a high-yielding source of cyclobutadiene , which in the absence of trapping agent yields the syn-dimer (59).

Effect of catalyst and solvent on the stereochemistry of Diels-Alder reactions between cyclopentadiene and 3-Phenylsulfinylprop-2-enoic acids and methyl esters

1984 ◽  
Vol 37 (8) ◽  
pp. 1677 ◽  
Author(s):  
SM Proust ◽  
DD Ridley
Keyword(s):  
Methyl Ester ◽  
Silica Gel ◽  
Reaction Rate ◽  
Methyl Esters ◽  
Diels Alder ◽  
Enoic Acid ◽  
Stannic Chloride ◽  
Spectroscopic Methods

In Diels-Alder reactions between cyclopentadiene and the isomeric 3-phenylsulfinylprop-2-enoic acids and methyl esters, greatest stereoselectivity (94% d.e.) results when methyl (2)-3-phenylsulfinylprop-2-enoate (7) and benzene solvent are used. The major diastereoisomer, methyl (2-endo,3-endo,S-syn)-3-phenylsulfinylnorborn-5-ene-2-carboxylate (8), also predominates when silica gel or aluminiumchloride catalysts are used, but is formed in lesser amount to the anti-epimer (9) in the presence of stannic chloride. Stereoselectivity of the reaction is decreased as reaction rate accelerates. Mixturesof all four possible diastereoisomers are formed in reactions with (E)-3-phenylsulfinylprop-2-enoic acid (15) and its methyl ester (16), and the ratios of products vary with catalyst and solvent. The stereochemistry at sulfur in these adducts has been correlated unambiguously by chemical and spectroscopic methods.

scholarly journals Hydrogen Peroxide Oxidation of Coordinated Thiocyanate Ion in cis- and trans-[Coen2NH3NCS]2+: The Preparation and Properties of trans-[Coen2NH3CN]2+

1973 ◽  
Vol 51 (24) ◽  
pp. 4152-4158 ◽  
Author(s):  
Albert Richard Norris ◽  
James William Lennox Wilson
Keyword(s):  
Hydrogen Peroxide ◽  
Spectral Properties ◽  
Peroxide Oxidation ◽  
Reaction Conditions ◽  
Thiocyanate Ion ◽  
Hydrogen Peroxide Oxidation ◽  
Percent Conversion ◽  
Cis And Trans ◽  
In Cis

The hydrogen peroxide oxidation of thiocyanate ion in cis- and trans-[Coen2NH3NCS]2+ leads to the formation of the corresponding cis- and trans-cyanoammine- and diamminebis(ethylenediamine)cobalt-(III) complexes. The spectral properties of the previously unreported trans-[Coe2NH3CN]2+ are reported and compared to the spectral properties of the cis-isomer.Observations are made concerning the reaction conditions which favor a high percent conversion of trans-[Coen2NH3NCS]2+ to trans-[Coen2NH3CN]2+.

Low solubility of alumina in enstatite and uncertainties in estimated palaeogeotherms

1978 ◽  
Vol 288 (1355) ◽  
pp. 471-486 ◽  
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Alumina Content ◽  
Equilibrium Solubility ◽  
Low Solubility

Spurious kinks in estimated palaeogeotherms may result from small errors in the calibration of the geothermometers and geobarometers. New data indicate that the equilibrium solubility of alumina in enstatite is even less than shown by recent studies, and that the slopes (d T /d P ) of the isopleths of equal alumina content are steeper than hitherto believed. Consequently, pressures of equilibration estimated from current formulations of the orthopyroxene-garnet geobarometer will be too high at high temperatures (> 1200 °C) and too low at low temperatures.

scholarly journals Environmental temperature during early life affects the personality of mosquitofish in adulthood

2021 ◽  
Author(s):  
Haifeng Li ◽  
Xinyu ZHang ◽  
Yi Wu ◽  
Feng ZHang ◽  
CHunlin Li
Keyword(s):  
Body Length ◽  
High Temperatures ◽  
Low Temperatures ◽  
Early Life ◽  
Environmental Temperature ◽  
Phenotypic Trait ◽  
Behavioral Syndrome ◽  
Growing Up ◽  
Female Fish ◽  
Behavioral Traits

Abstract Personality has been observed in a variety of animal taxa with important implications in ecology and evolution. Exploring the influence of environmental temperature during early life on personality could help to understand the ontogeny of this phenotypic trait in animals. In this study, we reared newborn mosquitofish Gambusia affinis at high (30°C) and low (25°C) water temperatures and measured their shyness and exploration upon sexual maturity. We tested the repeatability of each behavioral trait; the correlation between them; and the effects of rearing temperature, sex, and body length on the behaviors. When growing up at low temperatures, female fish exhibited repeatability in shyness and exploration, and males exhibited marginal repeatability in shyness. However, neither of the 2 behaviors were repeatable when the fish were reared at high temperatures. There was a negative correlation between shyness and exploration, indicating that the 2 behaviors comprise a behavioral syndrome in this species. Mosquitofish reared at high temperatures were more explorative than those reared at low temperatures, while there was no difference in shyness between the 2 treatments. Body length and sex had no significant effects on the average values of the 2 behaviors. The results indicate that environmental temperature during early life could shape the personality of mosquitofish and modify the average of the behavioral traits. These findings might provide insights to understand the ontogeny of animal personality and how changes in environmental temperature influence animal dispersal by shaping their personality.

PREPARATION OF ERUCIC AND NERVONIC ACIDS LABELLED WITH CARBON-14

1957 ◽  
Vol 35 (8) ◽  
pp. 757-760 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Enoic Acid ◽  
Nervonic Acid ◽  
Malonic Ester ◽  
Ester Synthesis ◽  
Trans Isomers ◽  
Carbon 14 ◽  
Cis And Trans Isomers ◽  
Cis And Trans

The malonic ester synthesis of nervonic acid (tetracos-15-enoic acid) has been modified so that the product consists of pure cis rather than a mixture of cis and trans isomers. The modified synthesis has been used for the preparation of C14-labelled erucic and nervonic acids.

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