The photochemistry of 1-cyano-2,3-benzobicyclo[4.2.0]octa-2,4,7-triene

1991 ◽  
Vol 69 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Christopher Owen Bender ◽  
Dean Sutherland Clyne ◽  
Douglas Dolman
Keyword(s):  
Key Words ◽  
Title Compound ◽  
Reaction Pathways ◽  
Direct Irradiation

The title compound (10) was prepared, along with the 4-cyano isomer (11), by the direct irradiation of 5-cyanobenzocyclooctatetraene (9); the yields were 82% (Φ10 = 0.0030) and 12% (Φ11 = 0.0004) respectively. Triene 10 was thermally and photochemically reactive. Heating solutions of 10 at 150 °C for 1 h gave COT 9 quantitatively. On direct irradiation 10 forms 5-cyanobenzosemibullvalene (12; 5%, Φ = 0.019), COT 9 (70%, Φ = 0.56), and 1-cyanonaphthalene (14%, Φ = 0.078). Sensitized irradiation of 10 gave 9 exclusively (92%, Φ = 0.88). COT 9 was also produced by the direct irradiation of semibullvalene 12 (75%, Φ = 0.13). Studies with deuterium labelled 10 suggest that the photoformation of COT 9 involves a simple electrocyclic opening of the cyclobutene ring of the triene. Additionally, the labelling results indicate that the formation of semibullvalene 12 from 10 derives from the operation of two reaction pathways, the major one of which appears to be a Zimmerman di-π-methane rearrangement. The mechanism proposed for the minor pathway to 12 has not been observed in other bicyclo[4.2.0]octatrienes. Key words: mechanisms, rearrangements, photochemistry, di-π-methane.

Proton-Assisted Switching of Reaction Pathways of Stilbene Analogues Brought by Direct Irradiation

2001 ◽  
Vol 3 (3) ◽  
pp. 409-411 ◽  
Author(s):  
Jinn-Hsuan Ho ◽  
Tong-Ing Ho ◽  
Robert S. H. Liu
Keyword(s):  
Reaction Pathways ◽  
Direct Irradiation ◽  
Stilbene Analogues

Synthesis and X-ray crystal structure determination of 3,4-diphenyl-6-(diphenylmethyl)-1,5-dioxa-2-thiane-2-oxide

1991 ◽  
Vol 69 (2) ◽  
pp. 185-188 ◽  
Author(s):  
L. Breau ◽  
N. K. Sharma ◽  
I. R. Butler ◽  
T Durst
Keyword(s):  
Crystal Structure ◽  
Key Words ◽  
Structure Determination ◽  
Title Compound ◽  
Heterocyclic Ring ◽  
Ring System ◽  
Sulfuryl Chloride ◽  
Similar Treatment ◽  
X Ray

Erythro and threo-1,2-diphenyl-2-tert-butylsulfinylethanols 5 and 8 were prepared from the condensation of the α-lithio derivative of benzyl-tert-butyl sulfoxide with benzaldehyde. Reaction of 5 with sulfuryl chloride gave the title compound, (2R*,3S*,4R*,6R*)-3,4-diphenyl-6-(diphenylmethyl)-1,5-dioxa-2-thiane-2-oxide 6, the first representative of a new heterocyclic ring system. Similar treatment of 8 resulted in the formation of 7, a stereoisomer of 6. This same compound was also obtained by photolysis of 6. In both 6 and 7 the S=O bond is in an axial orientation. Key words: sulfuryl chloride, reaction with β-hydroxy sulfoxides; 1,2-diphenyl-tert-butylsulfinylethanol; β-hydroxysulfoxides; β-sultines; N-chlorosuccinimide, reaction with β-hydroxysulfoxides.

The photochemistry of 2,3-benzobicyclo[4.2.0]octa-2,4,7-triene

1994 ◽  
Vol 72 (9) ◽  
pp. 1999-2004 ◽  
Author(s):  
Charlotte Lee Asplund ◽  
Christopher Owen Bender ◽  
Douglas Dolman
Keyword(s):  
Reaction Pathways ◽  
Unique Product ◽  
Direct Irradiation

2,3-Benzobicyclo[4.2.0]octa-2,4,7-triene (11) was prepared by Shapiro reaction from 2,3-benzobicyclo[4.2.0]octa-2,7-dien-4-one (10). Triene 11 was found to be thermally and photochemically reactive. Benzocyclooctatetraene (i.e., COT 12) was the unique product formed when solutions of 11 were heated at 150 °C for 5.5 h. The direct irradiation of triene 11 gave benzosemibullvalene (i.e., SB 14, 23%, Φ = 0.069), COT 12 (39%, Φ = 0.11), and naphthalene (8%, Φ = 0.025). Sensitized irradiations of 11 gave SB 14, (54%, Φ = 0.082), COT 12 (2%, Φ = 0.003), and naphthalene (4%, Φ = 0.009). Studies with deuterium-labelled triene (11a) indicated that the formation of SB 14 from the direct irradiation of triene 11 derives from the operation of two reaction pathways, the major one (83%) of which appears to be a Zimmerman di-π-methane rearrangement; the minor pathway involves a 1,2-shift of the C1—C6 bond to C1—C5. By contrast, SB 14 formed from sensitized irradiation appears to be provided uniquely by a Zimmerman di-π-methane rearrangement.

Reactions of Fe3(CO)12 and Fe(CO)5 with functionalized alkynes in CH3OH–KOH solution — The crystal structure of Fe2(CO)6(PPh3)[µ-η3-(H2CCCH2)]

2006 ◽  
Vol 84 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Giuliana Gervasio ◽  
Domenica Marabello ◽  
Enrico Sappa ◽  
Andrea Secco
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Coordination Mode ◽  
Iron Complexes ◽  
Reaction Pathways ◽  
X Ray ◽  
Iron Carbonyls ◽  
By Products

The complex Fe2(CO)7(H2CCCH2) (1) is obtained starting from a variety of functionalized alkynes that can release C3 fragments during the reactions with Fe3(CO)12 or Fe(CO)5 in CH3OH–KOH solutions. Owing to the oily nature of 1, it was reacted with triphenylphosphine, and the structure of the resulting title compound (1a) has been determined by X-ray analysis. Complex 1a shows a new coordination mode of a H2C=C=CH2 ligand to a diiron centre and is, to our knowledge, unprecedented. We have also found that 1 (and 1a) are by-products, and not intermediates in the formation of complex 3. A discussion of the possible reaction pathways is given.Key words: iron carbonyls, alkynols, CO and methanol activation, acetyl and acetate complexes, allenyl iron complexes, crystal structure.

Mechanistic variations in the formation of benzocyclooctatetraene from benzobicyclo[4.2.0]octa-2,4,7-triene

1996 ◽  
Vol 74 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Christopher Owen Bender
Keyword(s):  
Key Words ◽  
Chemical Yield ◽  
Major Product ◽  
Direct Photolysis ◽  
H Nmr ◽  
Step Procedure ◽  
Direct Irradiation ◽  
Initial Cleavage ◽  
A Minor ◽  
Mechanism Of The Reaction

Benzocyclooctatetraene (i.e., COT, 2) is the major product from the thermolysis and direct photolysis of 2,3-benzobicyclo[4.2.0]octa-2,4,7-triene (i.e., triene 1). It is also a minor product from the sensitized irradiation of 1. The mechanism of the reaction 1 → 2 was investigated using deuterium-labelled triene (i.e., 1a/b), which was prepared in a two-step procedure from a known triene mixture (1a) containing deuterium at both C-4 (43%) and C-5 (97%): the thermolysis of 1a led to labelled COT 2a, which upon direct irradiation (λ ≥ 310 nm) gave the deuterated triene mixture 1a/b in good chemical yield (61%) but in low quantum efficiency (Φ ≈ 0.0001). The COT produced from the direct irradiation (Corex filter) of 1a/b possessed different deuterium distributions than when generated thermally or from triplet sensitization (p-dimethylaminobenzophenone), as determined by 1H NMR integration. The observed deuterium-labelling patterns are in accord with a Zimmerman di-π-methane rearrangement being involved in formation of the COT from S1, of triene 1, while a mechanism proceeding by initial cleavage of the cyclobutene C1—C6 bond appears to operate during the thermal or sensitized (T1) generations of 2. Key words: mechanisms, rearrangements, photochemistry, di-π-methane.

Structure of 8-[4'-(3''-nitrobenzamido) benzamido]naphthalene-1,3,6-trisulfonate (NF-033), and molecular basis of its cellular toxicity

2000 ◽  
Vol 78 (1) ◽  
pp. 26-30
Author(s):  
Arthur Camerman ◽  
Donald Mastropaolo ◽  
Peter Nickel ◽  
Andrew Hempel ◽  
Norman Camerman
Keyword(s):  
Crystal Structure ◽  
Key Words ◽  
Title Compound ◽  
Molecular Basis ◽  
Water Molecules ◽  
High Toxicity ◽  
Cellular Toxicity ◽  
Anti Hiv ◽  
Oxygen Atoms

The title compound is one of a large number of compounds related to the drug suramin which have been found to have anti-HIV properties. However, its toxicity to uninfected cells is high. We crystallized the compound, determined its structure, and investigated the molecular basis for its high toxicity. The crystals are monoclinic, C2/c, a = 28.614(1), b = 10.031(0), c = 24.051(1) Å, β = 98.36(2)°, Z = 8, convergence at R = 0.066 for 4264 reflections with I > 2σ(I). The oxygen atoms of one of the sulfonate groups are disordered, as are several water molecules. Stereochemical comparisons with a segment of B-DNA have yielded a plausible explanation for the molecule's toxicity. Key words: crystal structure, cellular toxicity, stereochemistry, NF-033.

Multislice imaging of gastrointestinal stromal tumors

2018 ◽  
pp. 3-14
Keyword(s):  
Computed Tomography ◽  
Key Words ◽  
Gold Standard ◽  
Gastrointestinal Stromal Tumors ◽  
Mesenchymal Tumors ◽  
Stromal Tumors ◽  
Preferential Localization ◽  
Multislice Imaging ◽  
Computed Tomography Diagnosis

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the digestive tract (1%). These tumors express the CD 117 in 95% of cases. The stomach is the preferential localization (70%). Diagnosis is difficult and sometimes late. Progress of imaging has greatly improved the management and the prognosis. Computed tomography (CT) is the gold standard for diagnosis, staging, and treatment follow-up. The increasing recognition of GIST’s histopathology and the prolonged survival revealed some suggestive imaging aspects. Key words: gastro-intestinal stromal tumors; computed tomography; diagnosis

METHODS OF CONSULTING ON STUDYING THE DEGREE OF MOISTURE SUPPLY OF SLOPE LANDS FOR AGRICULTURAL PRODUCTION IN AZERBAIJAN

2018 ◽  
Author(s):  
Prof.RAE Aliev Z.H.
Keyword(s):  
Key Words ◽  
Agricultural Production ◽  
Soil Ecology ◽  
Arable Soil ◽  
Clean Technology ◽  
Agricultural Product ◽  
Current Information ◽  
Moisture Supply ◽  
Managerial System

The current information on moisture and the temperature of the ground in managerial system by production to agricultural product necessary, in the first place, for taking the operative decisions at development ecological clean technology irrigation under growing agricultural cultures to achieve the maximum harvest. Key words: aerospace methods, COW, moisture, moisture test, arable, soil, ecology, vafer humidity, drill, graduation, tool, etc.

PELAKSANAAN HUKUM KEWARISAN ISLAM DI PENGADILAN AGAMA BANTEN

ALQALAM ◽  
2013 ◽  
Vol 30 (1) ◽  
pp. 158
Author(s):  
Yusuf Somawinata
Keyword(s):  
Key Words ◽  
Islamic Law ◽  
Survey Methods ◽  
Adopted Children ◽  
Inheritance Law ◽  
Library Research ◽  
The Ideal

This article aims at describing the obseroance of wasiat wajibah (compulsory bequeathment) in the Islamic court of Banten, analyzing the provision of the substitute heir and adopted children in the Compilation of  Islamic Law (KHI). In addition, the ideal laws to manage the innheritance rules in Indonesia. This article is library research by using doctrinal approach and using case study and survey methods. The data was, then, analyzed by using analytical descriptive and analytical correlative methods. The result showed that the observance of wasiat wajibah in the Islamic court of  Banten employed by judges is by using the Mawali Hazairin’s Doctrine. The criteria of the adoption of substitute heir and adopted children in the KHI is the attempts of Ulama and many judgees junst in giving legal justice and certainty to the society.   Key Words: Islamic Inheritance Law, Compilation of Islamic Law, Islamic court of  Banten

Sign in / Sign up

Export Citation Format

Share Document