A nuclear magnetic resonance spectroscopic investigation of the headgroup motions of lysophospholipids in bilayers

Lipids ◽  
1984 ◽  
Vol 19 (1) ◽  
pp. 68-71 ◽  
Author(s):  
W. Wu ◽  
F. A. Stephenson' ◽  
J. T. Mason ◽  
C. Huang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Investigation ◽  
Nuclear Magnetic

A 19F nuclear magnetic resonance and Raman spectroscopic investigation of the reaction of iodine oxide pentafluoride with the Lewis acids, antimony and arsenic pentafluoride

1978 ◽  
Vol 56 (17) ◽  
pp. 2253-2258 ◽  
Author(s):  
Morley Brownstein ◽  
Ronald J Gillespie ◽  
John P. Krasznai
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Raman Spectroscopy ◽  
Magnetic Resonance ◽  
Low Temperature ◽  
Oxygen Atom ◽  
Spectroscopic Investigation ◽  
Lewis Acids ◽  
Raman Spectroscopic ◽  
Nuclear Magnetic

The reactions of IOF5 with SbF5 and with AsF5 have been investigated at low temperature by 19F nmr and Raman spectroscopy. It was found that SbF5 forms labile 1:1 and 2:1 complexes whereas AsF5 forms only a 1:1 complex. The IOF5 is bound through its oxygen atom to the Lewis acids AsF5, SbF5, or (SbF5)2.

A highly stereoselective intramolecular aldol condensation. Part I. Nuclear magnetic resonance spectroscopic investigation of the stereochemistry of the products derived from the reaction of 2,2′-O-methylene-bis-D-glycerose with base

1982 ◽  
Vol 60 (4) ◽  
pp. 390-414 ◽  
Author(s):  
Walter A. Szarek ◽  
B. Mario Pinto ◽  
Alan H. Haines ◽  
T. Bruce Grindley
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Investigation ◽  
Driving Force ◽  
Aldol Condensation ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Cannizzaro Reaction ◽  
High Degree ◽  
Nuclear Magnetic

The intramolecular aldol condensation of 2,2′-O-methylene-bis-D-glycerose has been found to yield only two of the four possible diastereomeric products. At higher base concentration or prolonged reaction times, these products undergo a Cannizzaro reaction. The stereochemistry of the products derived from the aldol condensation has been established by means of labelling experiments and by examination of the products by 1Hmr and 13Cmr spectroscopy. The major and minor products of the reaction have been identified as being 2-C-hydroxymethyl-2,4-O-methylene-D,L-ribose (7) and 2-C-hydroxymethyl-2,4-O-methylene-D,L-xylose (8), respectively. The preferential stabilization of these products in the reaction by means of intramolecular hemiacetal formation is proposed as a driving force for the high degree of stereoselectivity; this possibility is supported by the isolation of the bicyclic systems expected from such a reaction. Conditions have been chosen such that 7 is formed exclusively.

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