An efficient novel synthesis of β-(azuleno[1,2-b]benzothienyl)- and β-(azuleno[2,1-b]benzothienyl)-α,β-unsaturated ketones by the tropylium ion-mediated intramolecular furan ring-opening reaction and X-ray investigation of methyl ketone derivative1

2004 ◽  
Vol 2 (9) ◽  
pp. 1413-1418 ◽  
Author(s):  
Kimiaki Yamamura ◽  
Yuuko Houda ◽  
Masao Hashimoto ◽  
Takatomo Kimura ◽  
Makoto Kamezawa ◽  
...  
Keyword(s):  
Ring Opening ◽  
Methyl Ketone ◽  
Furan Ring ◽  
X Ray ◽  
Unsaturated Ketones ◽  
Novel Synthesis ◽  
Ring Opening Reaction

scholarly journals Attempted Synthesis and Unexpected β-Fragmentation of a Hindered β-Keto Nitroxide

2017 ◽  
Vol 70 (10) ◽  
pp. 1106 ◽  
Author(s):  
Chris Edwards ◽  
Peter C. Healy ◽  
W. Ken Busfield ◽  
Ezio Rizzardo ◽  
San H. Thang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ring Opening ◽  
Sodium Tungstate ◽  
Crystallographic Analysis ◽  
High Yield ◽  
Fragmentation Mechanism ◽  
Pentanoic Acid ◽  
X Ray ◽  
Ring Opening Reaction

The attempted synthesis of a β-keto imidazolidinone nitroxide by oxidation of the β-hydroxy imidazolidinone precursor with hydrogen peroxide and sodium tungstate led to an unexpected ring-opening reaction to produce 1,4-diazaspiro[4.5]dec-1-en-3-oxo-2-pentanoic acid 1-oxide (13) in high yield. The structure of 13 was confirmed by X-ray crystallographic analysis. A β-fragmentation mechanism is suggested for the oxidative ring-opening reaction.

scholarly journals Femtosecond x-ray spectroscopy of an electrocyclic ring-opening reaction

Science ◽  
2017 ◽  
Vol 356 (6333) ◽  
pp. 54-59 ◽  
Author(s):  
Andrew R. Attar ◽  
Aditi Bhattacherjee ◽  
C. D. Pemmaraju ◽  
Kirsten Schnorr ◽  
Kristina D. Closser ◽  
...  
Keyword(s):  
Ring Opening ◽  
X Ray ◽  
Ring Opening Reaction

scholarly journals Hydrophobic Modification of Nanocellulose via a Two-Step Silanation Method

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1035 ◽  
Author(s):  
Wensheng Lin ◽  
Xiaoyong Hu ◽  
Xueqing You ◽  
Yingying Sun ◽  
Yueqin Wen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Ring Opening ◽  
Chemical Characteristics ◽  
Surface Chemical ◽  
Hydrophobic Modification ◽  
Step Method ◽  
Water Contact ◽  
X Ray ◽  
Ring Opening Reaction

Dodecyltrimethoxysilane (DTMOS), which is a silanation modifier, was grafted onto nanocellulose crystals (NCC) through a two-step method using KH560 (ɤ-(2,3-epoxyproxy)propytrimethoxysilane) as a linker to improve the hydrophobicity of NCC. The reaction mechanism of NCC with KH560 and DTMOS and its surface chemical characteristics were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and HCl–acetone titration. These analyses confirmed that KH560 was grafted onto the surface of NCC through the ring-opening reaction, before DTMOS was covalently grafted onto the surface of NCC using KH560 as a linker. The grafting of NCC with DTMOS resulted in an improvement in its hydrophobicity due to an increase in its water contact angle from 0° to about 140°. In addition, the modified NCC also possessed enhanced thermal stability.

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