PREPARATION AND STEREOCHEMISTRY OF 1,2-O-(2′-HYDRO0XY-ETHYLIDENE)- AND 1,2-O-(HYDROXYISOPROPYLIDENE)-GLYCEROLS

1966 ◽  
Vol 44 (15) ◽  
pp. 1787-1793 ◽  
Author(s):  
P. A. J. Gorin ◽  
T. Ishikawa
Keyword(s):  
Hydrogen Bonding ◽  
Chemical Synthesis ◽  
Infrared Absorption ◽  
Hydroxyl Group ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Absorption Studies ◽  
Cis And Trans

The cis- and trans-isomers of 1,2-O-(2′-hydroxyethylidene)-glycerol (I and II) and 1,2-O-(hydroxyisopropylidene)-glycerol (V and VI) were prepared and their configurations assigned by stereospecific chemical synthesis. Equilibration of 1,2-O-(2′-cis-hydroxyethylidene)-L-glycerol (I) in acidified chloroform gave mainly 1,3-O-(2′-cis-hydroxyethylidene)-glycerol (III). In the 1,2-O-(hydroxyisopropylidene)-glycerol series, equilibration data and infrared absorption studies showed that hydrogen bonding of the O-(hydroxyisopropylidene) hydroxyl group was more pronounced in the cis-isomers.

Synthesis of the cis and trans isomers of 4-Chloro-L-proline, 4-Bromo-L-proline, and 4-Amino-L-proline

1967 ◽  
Vol 20 (7) ◽  
pp. 1493 ◽  
Author(s):  
RH Andreatta ◽  
V Nair ◽  
AV Robertson ◽  
WRJ Simpson
Keyword(s):  
Methyl Ester ◽  
Sodium Borohydride ◽  
Protecting Groups ◽  
Hydroxyl Group ◽  
Side Reactions ◽  
Trans Isomers ◽  
Azide Ion ◽  
Cis And Trans Isomers ◽  
Proline Derivatives ◽  
Cis And Trans

cis- and trans-4-Chloro- and 4-bromo-L-prolines have been synthesized stereospecifically, the key step being SN2 displacement of a free or substituted 4-hydroxyl group in suitably protected 4-hydroxy-L- prolines. Similar displacements with azide ion followed by reduction provide convenient routes to cis- and trans- 4-amino-L-proline. A less satisfactory pathway to cis-4-aminoproline is reduction of a 4- oximinoproline derivative. In the course of the syntheses, which involve a variety of protecting groups, 45 new L-proline derivatives have been prepared. Unexpected side reactions were the formation of cis-4-hydroxyprolinamide by the action of ammonia on trans-4- bromoproline, and the reduction by sodium borohydride of N- benzyloxycarbonyl-4-oximinoproline methyl ester to N-benzyloxycar- bonyl-4-oximinoprolinol.

THE INFRARED FREQUENCIES AND INTENSITIES OF THE HYDROXYL BAND OF ORTHO-ALKYL PHENOLS IN THE VAPOR PHASE

1962 ◽  
Vol 40 (1) ◽  
pp. 111-121 ◽  
Author(s):  
K. U. Ingold
Keyword(s):  
Vapor Phase ◽  
Hydroxyl Group ◽  
Trans Isomers ◽  
Polar Solvents ◽  
Cis And Trans Isomers ◽  
Stretching Vibration ◽  
Alkyl Phenols ◽  
Infrared Frequencies ◽  
Cis And Trans ◽  
Hydroxyl Band

The infrared frequencies and intensities of the fundamental stretching vibration of the hydroxyl group have been measured for a number of ortho-alkyl phenols in the vapor phase over a range of temperatures. Both quantities have been shown to depend on internal steric and environmental factors. The differences in enthalpy between the cis and trans isomers of several 2-tert-alkyl phenols have been measured, and it is concluded that the latter are not significantly stabilized relative to the former by solvation in non-polar solvents.

scholarly journals Identification of Anthocyanin Compounds in Butterfly Pea Flowers (Clitoria ternatea L.) by Ultra Performance Liquid Chromatography/Ultraviolet Coupled to Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4539
Author(s):  
Nguyen Minh Thuy ◽  
Vo Minh ◽  
Tran Ben ◽  
My Tuyen Thi Nguyen ◽  
Ho Ha ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Ultra Performance Liquid Chromatography ◽  
Negative Ion ◽  
Trans Isomers ◽  
Clitoria Ternatea ◽  
Flower Extract ◽  
Cis And Trans Isomers ◽  
Butterfly Pea ◽  
Cis And Trans

Butterfly pea flower have great sensory attraction, but they have not yet been used widely in Vietnam. Extracts of butterfly pea flowers can be used conveniently as a natural blue colorant for food products. In this study, the identification of anthocyanin compounds in butterfly pea flowers was performed by UPLC coupled with a UV and Mass spectrometer instrument. Positive and negative ion electrospray MS/MS chromatograms and spectra of the anthocyanin compounds were determined. By analyzing the chromatograms and spectra for each ion, five anthocyanins were identified in the butterfly pea flower extract; these were delphinidin-3-(6”‐p-coumaroyl)-rutinoside, cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl) glucose in both cis- and trans- isomers, cyanidin-3-(p-coumaroyl-glucoside) and delphinidin-3-pyranoside. Additionally, based on their intensity, it was determined that cyanidin-3-(p-coumaroyl-glucoside) was the most abundant anthocyanin, followed by cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl-glucoside), delphinidin-3-(6”-p-coumaroyl)-rutinoside and delphinidin-3-pyranoside. In this study, cyanidin derivatives were discovered in butterfly pea flower extract, where these compounds had not been detected in previous studies.

Unveiling the coexistence of cis- and trans-isomers in the hydrolysis of ZrO2: A coupled DFT and high-resolution photoelectron spectroscopy study

2020 ◽  
Vol 153 (24) ◽  
pp. 244308
Author(s):  
Ali Abou Taka ◽  
Mark C. Babin ◽  
Xianghai Sheng ◽  
Jessalyn A. DeVine ◽  
Daniel M. Neumark ◽  
...  
Keyword(s):  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Study ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Hydrolysis Of

PREPARATION OF ERUCIC AND NERVONIC ACIDS LABELLED WITH CARBON-14

1957 ◽  
Vol 35 (8) ◽  
pp. 757-760 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Enoic Acid ◽  
Nervonic Acid ◽  
Malonic Ester ◽  
Ester Synthesis ◽  
Trans Isomers ◽  
Carbon 14 ◽  
Cis And Trans Isomers ◽  
Cis And Trans

The malonic ester synthesis of nervonic acid (tetracos-15-enoic acid) has been modified so that the product consists of pure cis rather than a mixture of cis and trans isomers. The modified synthesis has been used for the preparation of C14-labelled erucic and nervonic acids.

Synthesis of cis and trans Isomers of D-Ring Linked Bis-Steroid Pyrazines from 16α-Bromo-17-oxosteroids

2002 ◽  
Vol 67 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zenon Łotowski ◽  
Jacek W. Morzycki ◽  
Izabella S. Niewczas ◽  
Marta Zdanowicz
Keyword(s):  
Gaseous Ammonia ◽  
Analogous Reaction ◽  
Air Oxidation ◽  
Trans Isomers ◽  
Hydrolysis Products ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Treatment of 16α-bromo-17-oxosteroids 1 and 2 with gaseous ammonia and successive air-oxidation afforded the cis and trans isomers of D-linked bis-steroid pyrazines. Analogous reaction of 1α-bromo-4-nor-5α-cholestan-2-one (3) led to unexpected hydrolysis products.

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