The mechanism of formation of alkoxybenzylidene [PhCHOR]+ ions from mixed dialkyl esters of phenylsuccinic acid upon electron ionization. Methoxy group migration between two carbonyl groups

1992 ◽  
Vol 27 (4) ◽  
pp. 527-528 ◽  
Author(s):  
I. Vidavsky ◽  
A. Mandelbaum
Keyword(s):  
Methoxy Group ◽  
Electron Ionization ◽  
Carbonyl Groups ◽  
Mechanism Of Formation ◽  
Phenylsuccinic Acid ◽  
Group Migration

A Tetrahydroxycalix[4]arene Derivative with All Bridges Monosubstituted with Methoxy Groups

Synthesis ◽  
2015 ◽  
Vol 47 (11) ◽  
pp. 1678-1682 ◽  
Author(s):  
Norbert Itzhak ◽  
Silvio Biali
Keyword(s):  
Crystal Structure ◽  
Methoxy Group ◽  
Crystal Structure Analysis ◽  
Protecting Groups ◽  
Carbonyl Groups ◽  
Arene Derivative ◽  
Oh Groups ◽  
X Ray ◽  
Methoxy Groups ◽  
Cis Isomer

Reduction of the carbonyl groups of tetrahydroxyketocalix[4]arene with NaBH4 in propan-2-ol, followed by heating the product to reflux in MeOH–H2SO4, yields a mixture of stereoisomers of the tetrahydroxycalix[4]arene derivative with all bridges monosubstituted by a methoxy group. To structurally characterize the compound, the mixture of isomers was derivatized by reaction with di-tert-butyl dicarbonate–DMAP. X-ray crystal structure analysis of the all-cis isomer of the product (obtained by fractional crystallization), corroborates the presence of Boc protecting groups at the lower rim (and thus underivatized OH groups in the starting material), and four methoxy groups at the bridges.

An unusual methoxy group migration: synthesis of cis-CH3OSF4NCO and cis-CH3OSF4NHC(O)OCH3

1986 ◽  
Vol 108 (12) ◽  
pp. 3526-3527 ◽  
Author(s):  
Joseph S. Thrasher ◽  
Jon L. Howell ◽  
Matthew. Clark ◽  
Alan F. Clifford
Keyword(s):  
Methoxy Group ◽  
Group Migration

Nucleophile–Electrophile Interactions in 1,8-Disubstituted Naphthalenes: Structures of Three 1-Naphthaldehydes and a 1-Naphthyl Methyl Ketone

1998 ◽  
Vol 54 (1) ◽  
pp. 73-81 ◽  
Author(s):  
J. C. Gallucci ◽  
D. J. Hart ◽  
D. G. J. Young
Keyword(s):  
Methoxy Group ◽  
Methyl Ketone ◽  
Carbonyl Groups ◽  
Formyl Group ◽  
Naphthalene Ring ◽  
Structural Differences ◽  
Acetyl Group

4,8-Dimethoxy-5-(tosyloxy)-1-naphthaldehyde (1) and 8-methoxy-5-(tosyloxy)-1-naphthaldehyde (2) crystallize such that the formyl groups approach coplanarity with the naphthalene rings. 4′,8′-Dimethoxy-5′-(tosyloxy)-1′-acetonaphthone (4), however, crystallizes such that the acetyl group approaches orthogonality to the naphthalene ring. In all three compounds the methoxy group and carbonyl groups exhibit a leaning effect typical of nucleophile–electrophile interactions in 1,8-disubstituted naphthalenes. 8-(Benzoyloxy)-4-methoxy-1-naphthaldehyde (3) crystallizes with the formyl group nearly coplanar to the naphthalene ring and does not exhibit the leaning effect. It is suggested that these structural differences are largely due to differences in the steric requirements of formyl and acetyl groups.

ChemInform Abstract: An Unusual Methoxy Group Migration: Synthesis of cis-CH3OSF4NCO and cis-CH3OSF4NHC(O)OCH3.

1986 ◽  
Vol 17 (42) ◽  
Author(s):  
J. S. THRASHER ◽  
J. L. HOWELL ◽  
M. CLARK ◽  
A. F. CLIFFORD
Keyword(s):  
Methoxy Group ◽  
Group Migration

Chemical and orientational imaging of polymeric samples

1994 ◽  
Vol 52 ◽  
pp. 68-69
Author(s):  
H. Ade ◽  
B. Hsiao ◽  
G. Mitchell ◽  
E. Rightor ◽  
A. P. Smith ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Carbonyl Groups ◽  
Aromatic Rings ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
Polymeric Samples ◽  
X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

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