Perchloric acid-catalyzed acetic anhydride enol acetylation of steroidal .DELTA.-3-ketones

1968 ◽  
Vol 33 (8) ◽  
pp. 3109-3113 ◽  
Author(s):  
A. J. Liston ◽  
P. Toft
Keyword(s):  
Acetic Anhydride ◽  
Perchloric Acid ◽  
Acid Catalyzed

SUBSTITUTION OF ACYCLIC SUGAR ACETALS: RATE OF PERCHLORIC ACID CATALYZED ACETOLYSIS OF 2,3,4,5,6-PENTA-O-ACETYL-D-GLUCOSE DIETHYL DITHIOACETAL AND 1,2,3,4,5,6-HEXA-O-ACETYL-D-GLUCOSE S-ETHYL MONOTHIOACETAL

1966 ◽  
Vol 44 (15) ◽  
pp. 1773-1782 ◽  
Author(s):  
Norman H. Kurihara ◽  
Edgar Page Painter
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Perchloric Acid ◽  
Rate Constants ◽  
Acetoxy Group ◽  
Rate Determining Step ◽  
Conjugate Acid ◽  
Acid Catalyzed ◽  
Sugar Derivatives

The rate constants for the perchloric acid catalyzed substitution of one ethylthio group of 2,3,4,5,6-penta-O-acetyl-D-glucose diethyl dithioacetal (Va) and the acetoxy group bonded to C1 of 1,2,3,4,5,6-hexa-O-acetyl-D-glucose S-ethyl monothioacetal (VIa) have been measured when the substrates were dissolved in solutions of acetic acid and acetic anhydride. The rate-determining step is interpreted to be the dissociation of the substrate conjugate acid to give a carbonium–sulfonium cation. The rate constants indicate that acyclic sugar derivatives are substituted faster than cyclic (pyranose) derivatives, and that an acetoxy group is substituted faster than an ethylthio group.

Perchloric acid catalyzed acylation of anisole

1976 ◽  
Vol 10 (3) ◽  
pp. 363-364
Author(s):  
B. M. Savin ◽  
S. A. Kesler
Keyword(s):  
Perchloric Acid ◽  
Acid Catalyzed

The acid-catalyzed demetalation of 1-(tri-n-butylstannyl)-2-phenylethyne. A surprisingly small β-stannyl effect

1996 ◽  
Vol 74 (7) ◽  
pp. 1366-1368 ◽  
Author(s):  
I. Egle ◽  
V. Gabelica ◽  
A.J. Kresge ◽  
T.T. Tidwell
Keyword(s):  
Key Words ◽  
Isotope Effect ◽  
Acid Concentration ◽  
Rate Constant ◽  
Perchloric Acid ◽  
Hydronium Ion ◽  
Stabilizing Effect ◽  
Aromatic Product ◽  
Acid Catalyzed ◽  
The Difference

Rates of conversion of 1-(tri-n-butylstannyl)-2-phenylethyne to phenylethyne in H2O and D2O solutions of perchloric acid were found to be proportional to acid concentration, giving the hydronium ion rate constant [Formula: see text] and the isotope effect [Formula: see text]. The magnitude of this isotope effect suggests that the reaction occurs by rate-determining hydron transfer to the substrate, producing a vinyl carbocation; this carbocation then loses its tributylstannyl group, giving phenylacetylene as the only detectable aromatic product. The hydronium ion rate constant, when compared to the rates of protonation of phenylethyne and 1-(trimethylsilyl)-2-phenylethyne, gives a β-stannyl stabilizing effect of δΔG≠ = 6.6 kcal mol−1 and a differential β-stannyl/β-silyl effect of δΔG≠ = 3.2 kcal mol−1. These stabilizations are very much smaller than previously reported β-stannyl effects. Possible reasons for the difference are suggested. Key words: β-stannyl effect, β-silyl effect, carbocation stabilization, protodemetalation.

ChemInform Abstract: Silica Supported Perchloric Acid Catalyzed Rapid N-Formylation under Solvent-Free Conditions.

ChemInform ◽  
2012 ◽  
Vol 43 (32) ◽  
pp. no-no
Author(s):  
Mohd. Imran Ansari ◽  
Mohd. Kamil Hussain ◽  
Nisha Yadav ◽  
Puneet K. Gupta ◽  
K. Hajela
Keyword(s):  
Perchloric Acid ◽  
Solvent Free ◽  
Solvent Free Conditions ◽  
Acid Catalyzed

Oxidation of 1,4-dimethylcyclohexane by perchloric acid catalyzed by polyphenylferrosiloxane

1998 ◽  
Vol 47 (3) ◽  
pp. 435-437 ◽  
Author(s):  
V. S. Kulikova ◽  
M. M. Levitsky ◽  
A. F. Shestakov ◽  
A. E. Shilov
Keyword(s):  
Perchloric Acid ◽  
Acid Catalyzed

ChemInform Abstract: Sulfamic Acid Catalyzed Acetylation of Alcohols and Phenols with Acetic Anhydride.

ChemInform ◽  
2010 ◽  
Vol 29 (48) ◽  
pp. no-no
Author(s):  
T.-S. JIN ◽  
Y.-R. MA ◽  
Z.-H. ZHANG ◽  
T.-S. LI
Keyword(s):  
Acetic Anhydride ◽  
Sulfamic Acid ◽  
Acid Catalyzed

Determination of Mercaptosilanes by Perchloric Acid-Catalyzed Acetylation and with Mercuric Acetate.

1964 ◽  
Vol 36 (6) ◽  
pp. 1156-1157 ◽  
Author(s):  
Abe. Berger ◽  
J. A. Magnuson
Keyword(s):  
Perchloric Acid ◽  
Mercuric Acetate ◽  
Acid Catalyzed

H14[NaP5W30O110]: A heteropoly acid catalyzed acetylation of alcohols and phenols in acetic anhydride

2006 ◽  
Vol 253 (1-2) ◽  
pp. 16-19 ◽  
Author(s):  
Majid M. Heravi ◽  
Farahnaz K. Behbahani ◽  
Fatemeh F. Bamoharram
Keyword(s):  
Acetic Anhydride ◽  
Heteropoly Acid ◽  
Acid Catalyzed
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