Stereochemistry of 1,2-elimination reactions at the E2–E1cB interface—tert-butyl 3-tosyloxybutanoate and its thioester

2008 ◽  
Vol 6 (9) ◽  
pp. 1641 ◽  
Author(s):  
Jerry R. Mohrig ◽  
David G. Alberg ◽  
Craig H. Cartwright ◽  
Mary Kay H. Pflum ◽  
Jeffrey S. Aldrich ◽  
...  
Keyword(s):  
Tert Butyl ◽  
Elimination Reactions

E2C mechanism in elimination reactions. III. Dehydrobromination of tert-butyl bromide in acetone

1972 ◽  
Vol 94 (7) ◽  
pp. 2228-2235 ◽  
Author(s):  
A. J. Parker ◽  
M. Ruane ◽  
D. A. Palmer ◽  
Saul Winstein
Keyword(s):  
Butyl Bromide ◽  
Tert Butyl ◽  
Elimination Reactions

Secondary α-deuterium kinetic isotope effects for the E2 reaction of the 2-phenylethyl halides with tert-butoxide ion in tert-butyl alcohol

1985 ◽  
Vol 63 (1) ◽  
pp. 100-102 ◽  
Author(s):  
Peter James Smith ◽  
Kanchugarakoppal S. Rangappa ◽  
Kenneth Charles Westaway
Keyword(s):  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Order Rate Constant ◽  
Butyl Alcohol ◽  
Tert Butyl ◽  
Kinetic Isotope ◽  
Tert Butyl Alcohol ◽  
Elimination Reactions ◽  
Leaving Groups ◽  
High Base

Secondary α-deuterium kinetic isotope effects have been determined for the elimination reactions of 2-phenylethyl halides with tert-butoxide in tert-butyl alcohol at 40 °C in the presence and absence of the crown ether 18C6. The second-order rate constant k2 and the normal (kH/kD)α effect remained constant when the tert-butoxide concentration was varied for reaction of the iodo and bromo compounds. However, both the magnitude of k2 and the secondary α-deuterium isotope effect were significantly dependent on [t-BuO−] when chlorine and fluorine are the leaving groups. It is noteworthy that (kH/kD)α is inverse for the reaction of both the chloro and fluoro compounds at "low" base concentrations and normal at "high" base concentrations. These results are discussed in terms of both syn- and anti-elimination pathways promoted by various associated and dissociated base species. It is suggested that the (kH/kD)α effect may be useful as a criterion for determining the stereochemistry of E2 elimination reactions.

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