An α-diketone from the condensation product of glucose and ethyl acetoacetate

1964 ◽  
Vol 17 (10) ◽  
pp. 1174 ◽  
Author(s):  
LK Dalton
Keyword(s):  
Hydrogen Peroxide ◽  
Solid State ◽  
Hydrogen Chloride ◽  
Ethyl Acetoacetate ◽  
Condensation Product ◽  
Side Chain ◽  
Furoic Acid ◽  
Aliphatic Side Chain ◽  
Benzilic Acid ◽  
Reversible Cyclization

When the product from the condensation of glucose and ethyl acetoacetate, ethyl 2-D-arabino-tetrahydroxybutyl-5-methyl-4-furoate (Ia), is heated in ethanolic hydrogen chloride, an a-diketone (IVa) is produced. It exists as a mono-enol in solution and in the solid state. Although this diketone is formed with an aliphatic side chain, there is at first a predominant, but reversible, cyclization to the "difuran" (II). With hydrogen peroxide the diketone yields 2-carboxymethy1-5- methyl-4-furoic acid (VII), and with alkali it undergoes a benzilic acid rearrangement.

Synthesis and solid state structures of macromolecular cylindrical brushes with varying side chain length

Polymer ◽  
2004 ◽  
Vol 45 (12) ◽  
pp. 4009-4015 ◽  
Author(s):  
Bin Zhang ◽  
Shanju Zhang ◽  
Lidia Okrasa ◽  
Tadeusz Pakula ◽  
Tim Stephan ◽  
...  
Keyword(s):  
Solid State ◽  
Chain Length ◽  
Side Chain ◽  
Side Chain Length ◽  
Solid State Structures

Thermosetting Mechanism Study of Organosilicon Polymer Containing Carborane by Solid-State NMR Spectroscopy

1999 ◽  
Vol 576 ◽  
Author(s):  
H. Kimura ◽  
K. Okita ◽  
M. Ichitani ◽  
M. Yonezawa ◽  
T. Sugimoto
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Main Chain ◽  
Addition Reaction ◽  
Side Chain ◽  
Mechanism Study ◽  
Nmr Method ◽  
Organosilicon Polymer ◽  
Thermal Stable

ABSTRACTThe thermosetting mechanism of an organosilicon polymer containing carborane has been studied utilizing the 13and 29Si solid-state NMR method. The polymer having C≡C bonds in the main chain and CH═CH2, Si-H bonds, and carborane in the bulky side chain, shows a very highly thermal stability in air by curing. From 13C and 29Si NMR spectra of the polymer, it was found that the intermolecular cross-linking reactions of the polymer was due to (1) the diene reaction between Ph-C≡C and C≡C and (2) the addition reaction between side chain terminal and Ph-C≡C and between CH═CH2 and Si–H, and a very highly thermal stable structure is formed.

scholarly journals Corrigendum: Solid-State NMR Measurements of Asymmetric Dipolar Couplings Provide Insight into Protein Side-Chain Motion

2012 ◽  
Vol 51 (40) ◽  
pp. 9959-9959
Author(s):  
Paul Schanda ◽  
Matthias Huber ◽  
Jérôme Boisbouvier ◽  
Beat H. Meier ◽  
Matthias Ernst
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Dipolar Couplings ◽  
Side Chain ◽  
Side Chain Motion ◽  
Insight Into

scholarly journals Deep search for hydrogen peroxide toward pre- and protostellar objects

2020 ◽  
Vol 636 ◽  
pp. A114
Author(s):  
G. W. Fuchs ◽  
D. Witsch ◽  
D. Herberth ◽  
M. Kempkes ◽  
B. Stanclik ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Solid State ◽  
Water Reservoir ◽  
Reaction Network ◽  
Reaction Scheme ◽  
Young Stellar Objects ◽  
Model Parameters ◽  
Stellar Objects ◽  
Additional Information ◽  
Water Formation

Context. In the laboratory, hydrogen peroxide (HOOH) was proven to be an intermediate product in the solid-state reaction scheme that leads to the formation of water on icy dust grains. When HOOH desorbs from the icy grains, it can be detected in the gas phase. In combination with water detections, it may provide additional information on the water reaction network. Hydrogen peroxide has previously been found toward ρ Oph A. However, further searches for this molecule in other sources failed. Hydrogen peroxide plays a fundamental role in the understanding of solid-state water formation and the overall water reservoir in young stellar objects (YSOs). Without further HOOH detections, it is difficult to assess and develop suitable chemical models that properly take into account the formation of water on icy surfaces. Aims. The objective of this work is to identify HOOH in YSOs and thereby constrain the grain surface water formation hypothesis. Methods. Using an astrochemical model based on previous work in combination with a physical model of YSOs, the sources R CrA-IRS 5A, NGC C1333-IRAS 2A, L1551-IRS 5, and L1544 were identified as suitable candidates for an HOOH detection. Long integration times on the APEX 12 m and IRAM 30 m telescopes were applied to search for HOOH signatures in these sources. Results. None of the four sources under investigation showed convincing spectral signatures of HOOH. The upper limit for HOOH abundance based on the noise level at the frequency positions of this molecule for the source R CrA-IRS 5A was close to the predicted value. For NGC 1333-IRAS 2A, L1544, and L1551-IRS 5, the model overestimated the hydrogen peroxide abundances. Conclusions. HOOH remains an elusive molecule. With only one secure cosmic HOOH source detected so far, namely ρ Oph A, the chemical model parameters for this molecule cannot be sufficiently well determined or confirmed in existing models. Possible reasons for the nondetections of HOOH are discussed.

Expeditious Base-free Solid-State Reaction between Phenyl Boronates and Hydrogen Peroxide on Silica Gel

2022 ◽  
Author(s):  
Li Zhang ◽  
Qianqian Chen ◽  
Li Yang ◽  
Yining He ◽  
Keke Guo ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Solid State ◽  
Silica Gel ◽  
Solid State Reaction

The conversion of phenyl boronates to phenol by hydrogen peroxide (H2O2) usually requires the base as the chemical assistant. In this work, we reported a base-free reaction between the phenyl...

Peptide folding induced by Cα-methylated, chiral α-acids with a long aliphatic side chain

2006 ◽  
pp. 270-271
Author(s):  
Marco Crisma ◽  
Cristina Peggion ◽  
Fernando Formaggio ◽  
Bernard Kaptein ◽  
Quirinus B. Broxterman ◽  
...  
Keyword(s):  
Peptide Folding ◽  
Side Chain ◽  
Aliphatic Side Chain
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