ISSN:
0894-3230
Schlagwort(e):
mechanistically optimized intramolecular catalysis
;
ester hydrolysis
;
molecular reactivity
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
---The hydrolysis of the 2′,2′,2′-trifluoroethyl monoester of 1,8-naphthalic acid (1) proceeds via the monoanion with the intermediate formation of the corresponding anhydride. The rate constant for the formation of 1,8-naphthalic anhydride (2) is ca 2500 times faster than its rate of hydrolysis. The isotope effect in the plateau region and theoretical calculations at the PM3 level suggest that elimination of the alkoxide is the rate-limiting step for the reaction. Accordingly, decomposition of the isopropyl monoester of naphthalic acid proceeds 104 times slower than the spontaneous decomposition of 1. The remarkably high rate of monoester decomposition derives from the special configuration of the substrates and important contributions that arise from relief of torsional strain, which clearly includes electron redistribution due to the decrease in steric hindrance to resonance and the fact that proximity obviates solvation. © 1997 John Wiley & Sons, Ltd.
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
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