Mass Spectra of O-Isopropylidene Derivatives of Pentoses and Hexoses

1964 ◽  
Vol 86 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Don C. De Jongh ◽  
K. Biemann
Keyword(s):  
Mass Spectra ◽  
Isopropylidene Derivatives ◽  
Derivatives Of

Inductive effect in EI-mass spectra of some 5,6-dihalogenides and 5,6-halohydrins of 5α-cholestan-3β-ol and 3β-acetoxy-5α-cholestane

1982 ◽  
Vol 47 (11) ◽  
pp. 2946-2960 ◽  
Author(s):  
Antonín Trka ◽  
Alexander Kasal
Keyword(s):  
Mass Spectra ◽  
Inductive Effect ◽  
Molecular Ions ◽  
Hydroxyl Group ◽  
Halogen Atoms ◽  
Derivatives Of

Partial EI-mass spectra of 3β-hydroxy- and 3β-acetoxy-5α-cholestanes substituted in positions 5α-, 6β- or 5α,6β- with a hydroxyl group or halogen atoms (fluorine, chlorine, bromine) are presented. The molecular ions of 5α,6β-disubstituted derivatives of 3β-hydroxy-5α-cholestane (or of its 3-acetate) are considerably more stable than the corresponding monosubstituted derivatives if at least one of the pair of the vicinal substituents is chlorine or fluorine. This increase in stability, most striking in 5α- and 6β-fluoro compounds, is explained by the inductive effect.

Mass spectra of dicyanomethylene derivatives of benzophenone analogs

1983 ◽  
Vol 18 (11) ◽  
pp. 457-461 ◽  
Author(s):  
Ching-Bore Wang ◽  
Guor-Rong Her ◽  
J. Throck Watson
Keyword(s):  
Mass Spectra ◽  
Derivatives Of

ω-Aldehydo Sugars Prepared by Ninhydrin Oxidation

1974 ◽  
Vol 52 (23) ◽  
pp. 3905-3912 ◽  
Author(s):  
Alan R. Gibson ◽  
Laurence D. Melton ◽  
Keith N. Slessor
Keyword(s):  
Mass Spectra ◽  
Oxidative Deamination ◽  
Ninhydrin Reaction ◽  
Derivatives Of

The reaction of ninhydrin with 6-amino-6-deoxy-hexopyranosyl sugars has been investigated. 6-Aldehydocyclohexaamylose and 1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose have been prepared by oxidative deamination of 6-amino-deoxycyclohexaamylose and 6-amino-6-deoxy-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose, respectively, using ninhydrin. The preparation of the two aldehydes by the ninhydrin reaction is compared with the method of photolysis of the corresponding azido sugars. The mass spectra of the perdimethylsilyl derivatives of cyclohexaamylose and O-methyl oxime of 6-aldehydocyclohexaamylose have been recorded.

Thio derivatives of β-diketones and their metal chelates. XIX. Metal chelates of two new fluorinated Monothio-β-diketones and their mass spectra

1975 ◽  
Vol 28 (6) ◽  
pp. 1249 ◽  
Author(s):  
SE Livingstone ◽  
N Saha
Keyword(s):  
Mass Spectra ◽  
Metal Chelates ◽  
The Novel ◽  
Copper Chelates ◽  
Derivatives Of

The nickel(II), palladium(II), platinum(II), copper(II), zinc(II) and rhodium(III) chelates of the new fluorinated monothio-β-diketones RC(SH)=CHCOCF3 (R = Pri, Bui) and the iron(III), ruthenium(III) and cobalt(III) chelates of PriC(SH)=CHCOCF3 have been prepared. The mass spectra of all but the two copper chelates have been obtained. The novel features of the spectra are the occurrence of the ions M-(R-H), M-R, and M-LH and the loss of H2S from the ions M-LH and M-L.

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