E2C mechanism in elimination reactions. VI. Primary hydrogen isotope effects on rates of E2 reactions of alicyclics
Primany hydrogen isotope effects on the rates of bimolecular elimination reactions of some cyclohexyl tosylates and bromides are small (k/sup H/k/sup D/ approximately 2 -3) for very E2C-like reactions, pass through a maximum of 6 for more E2H-like reactions, and are small again (2 -- 3) for very E2H-like reactions. Movement from the E2C to the E2H side of the spectrum has been achieved by increasing the acidity of the substrate, by increasing the hydrogen basicity of the base, and by changing the leaving group from tosylate to bromide. Differences between k/sup H//k/sup D/ values, as measured by intramolecular competition vs. intermolecular rate comparisons, may be due to a secondary hyperconjugative isotope effect. (auth)
- Research Organization:
- Australian National Univ., Canberra
- NSA Number:
- NSA-29-020665
- OSTI ID:
- 4330592
- Journal Information:
- J. Org. Chem., v. 39, no. 4, pp. 534-539, Journal Name: J. Org. Chem., v. 39, no. 4, pp. 534-539; ISSN JOCEA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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