ChemInform Abstract: Synthetic Studies of Pyridomycin. Part 4. Syntheses of Some Twelve-membered Ring Compounds Designed for Construction of Intact Ring System with Exocyclic (Z)-s- Butylidene Side Chain in Pyridomycin.

1986 ◽  
Vol 17 (10) ◽  
Author(s):  
M. KINOSHITA ◽  
Y. MORI
Keyword(s):  
Ring System ◽  
Membered Ring ◽  
Side Chain ◽  
Ring Compounds ◽  
Synthetic Studies

Synthetic Studies on Maitotoxin. 1. Stereoselective Synthesis of the C′D′E′F′-Ring System Having a Side Chain

2008 ◽  
Vol 10 (9) ◽  
pp. 1675-1678 ◽  
Author(s):  
Masayuki Morita ◽  
Seishi Ishiyama ◽  
Hiroyuki Koshino ◽  
Tadashi Nakata
Keyword(s):  
Stereoselective Synthesis ◽  
Ring System ◽  
Side Chain ◽  
Synthetic Studies ◽  
F Ring

Heterocyclische Siebenring-Verbindungen, XXX Synthese und Eigenschaften von 4-Methoxy-1,5-benzothiazepin, einem einfachen Vertreter des 1,4-Thiazepin-Ringsystems/ Heterocyclic Seven-Membered Ring Compounds, XXX Synthesis and Properties of 4-Methoxy-1,5-benzothiazepine, a Simple Derivative of the 1,4-Thiazepine Ring System

1987 ◽  
Vol 42 (2) ◽  
pp. 217-220 ◽  
Author(s):  
Hans Hofmann ◽  
Herbert Fischer
Keyword(s):  
Dimethyl Sulfate ◽  
Ring System ◽  
Membered Ring ◽  
Ring Compounds ◽  
Simple Derivative

Abstract Alkylation of 1,5-benzothiazepin-4(5H)-one (1) with dimethyl sulfate and base yields the N-methyl compound 2 whereas with trimethyloxonium fluoroborate the lactimether 3, a simple derivative of the unknown, 1,4-thiazepine is obtained. Compound 3 eliminates sulfur on heating in toluene, yielding 2-methoxy-quinoline. Oxidation of 3 with peracid produces the stable 1,1- dioxide (4).

Synthese und Kristallstruktur siebengliedriger kohlenstoffhaltiger Schwefel-Stickstoffringe / Synthesis and Crystal Structure of Seven-M embered Sulfur Nitrogen Rings Containing Carbon

1987 ◽  
Vol 42 (10) ◽  
pp. 1249-1252 ◽  
Author(s):  
Herbert W. Roesky ◽  
Nasreddine Benmohamed ◽  
Klaus Keller ◽  
Nayla Keweloh ◽  
Mathias Noltemeyer ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Ring System ◽  
Membered Ring ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Ring Compounds

Abstract The reaction of ClSCF2CF2SCl and (Me3SiN)2SR2 proceeds with formation of the seven-membered ring compounds 4a, R = CH3, and 4b, R = C2H5. 4a was shown by an X-ray structure determination to contain a non-planar ring system.

The Chemistry of Pyrrolic Compounds. LXIII. Synthetic Studies of Petroporphyrins With Fused Six-Membered Ring Systems

1990 ◽  
Vol 43 (5) ◽  
pp. 825 ◽  
Author(s):  
PS Clezy ◽  
JK Prashar
Keyword(s):  
Intramolecular Cyclization ◽  
Membered Ring ◽  
Stannic Chloride ◽  
Side Chain ◽  
Ring Systems ◽  
Synthetic Studies

Several approaches to the synthesis of porphyrins bearing fused six- membered ring systems were explored with the aim of obtaining the petroporphyrin (4a). This was ultimately achieved by an intramolecular cyclization of a porphyrin with a propanoyl chloride side chain in the presence of stannic chloride. Methylation of the intermediate ketone with CH3Li and reduction of the resultant alcohol with NaBH3CN/Znl2 furnished (4a).

Isomerization of the Isoprene Hydroxy Nitrates and Formation of Orthonitrite Compounds

2019 ◽  
Author(s):  
Gabriel da Silva
Keyword(s):  
Hydroxy Group ◽  
Peroxyl Radical ◽  
Branching Fractions ◽  
Membered Ring ◽  
Low Energy ◽  
Peroxyl Radicals ◽  
Aerosol Formation ◽  
Subsequent Removal ◽  
Ring Compounds ◽  
Group Migration

Atmospheric oxidation of isoprene produces significant yields of eight unique nitrate 11 compounds, each with a β- or δ-hydroxy group. These isoprene hydroxy nitrates (ISOPNs) 12 significantly impact upon global NOx budgets, O3 levels, and aerosol formation. 13 Uncertainties exist, however, in our understanding of ISOPN chemistry, particularly in their 14 yields from the reaction of isoprene peroxyl radicals with NO. This study describes novel 15 isomerization reactions of the ISOPNs, identified through the application of computational 16 chemistry techniques. These reactions produce saturated polycyclic orthonitrite compounds 17 via attack of the R–NO2 group on the vinyl moiety. For the δ-hydroxy nitrates, low-energy 18 isomerization pathways exist to six-membered ring compounds that are around 5 kcal mol-1 19 exothermic. These reactions proceed with barriers around 15 kcal mol-1 below the 20 respective peroxyl radical + NO reactants and yield orthonitrites that can further isomerize 21 to β-hydroxy ISOPNs. Moreover, the δ-hydroxy nitrates can directly interconvert with their β 22 substituted counterparts via NO3 group migration, with barriers that are lower yet. It follows 23 that β-hydroxy nitrates may be stabilized in the δ-hydroxy form, and vice versa. Moreover, 24 the lowest-energy pathway for dissociation of the δ-hydroxy ISOPNs is for the formation of 25 β-hydroxy alkoxyl radicals, and because of this established branching fractions between the 26 various isoprene peroxyl radicals may require re-evaluation. The results presented here also 27 suggest that ISOPNs may be stabilized to some extent in their saturated orthonitrite forms, 28 which has implications for both the total nitrate yield and for their subsequent removal by 29 OH, O3, and photolysis.<br><br>

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