Characterization of the major isomers of substituted tetrahydro-2 H -pyrans from 1,3,5-triarylpentane-1,5-diols by p -toluenesulfonic acid treatment

2018 ◽  
Vol 1156 ◽  
pp. 684-689 ◽  
Author(s):  
Rengasamy Chithiravel ◽  
Kandasamy Rajaguru ◽  
Shanmugam Muthusubramanian ◽  
Nattamai Bhuvanesh
2000 ◽  
Vol 108 (1254) ◽  
pp. 196-201 ◽  
Author(s):  
Tatsuya SHIRAKAMI ◽  
Takahiko NAKAOKI ◽  
Hideki OHMOTO ◽  
Atsushi KISHIGAMI ◽  
Kazuyori URABE

Holzforschung ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 933-942 ◽  
Author(s):  
Qianli Ma ◽  
Liheng Chen ◽  
Ruibin Wang ◽  
Rendang Yang ◽  
J.Y. Zhu

AbstractLignin nanoparticles (LNPs) from renewable lignocelluloses can be a valuable building block for a variety of applications and could contribute to the economic development in rural agricultural communities. Current technologies for producing LNPs are not cost effective and use toxic solvents. In this study, LNPs were produced by fractionating poplar wood at ≤80°C with a recyclable hydrotropep-toluenesulfonic acid (p-TsOH) in an aqueous system. The dissolved lignin was separated as LNPs simply by diluting the spent liquor (SL) to the minimal hydrotrope concentration (HCmin) of 11.5%. Thep-TsOH, a solid acid, can be easily recycled by re-concentrating the diluted SL after lignin separation. The LNP size, morphology, and surface charge were controlled by the dilution ratio, speed, pH, and ionic strength of the LNP sol. The LNPs were analyzed by dynamic light scattering (DLS) and found to be fairly stable in terms of mean particle size and surface charge over a period of 2 weeks. Fractionation conditions also affected LNP properties.


2018 ◽  
Author(s):  
P. Khamkhom ◽  
C. Chananonnawathorn ◽  
W. Hincheeranun ◽  
S. Limwichean ◽  
P. Eiamchai ◽  
...  

1979 ◽  
Vol 32 (12) ◽  
pp. 2681 ◽  
Author(s):  
A Castonguay ◽  
Y Berger

In the presence of the amino acid (S)-(-)-proline, 1,3-dihydroxyanthraquinone (1) is alkylated by phenylacetaldehyde to give an anomeric mixture of lactols (2). The lactols are oxidized to the corresponding lactone (3) by manganese dioxide or chromic acid. Treatment of (2) with p-toluenesulfonic acid yields the expected enol ether (4) along with the substitution product (5). Mass spectrometry fragmentation, high-resolution 1H N.M.R. and 13C n.m.r, studies of these compounds are discussed.


Sign in / Sign up

Export Citation Format

Share Document