THERMODYNAMICS OF HYDROLYSIS OF ALIPHATIC KETALS - ENTROPY COMPONENT OF STERIC EFFECTS

被引:27
作者
WIBERG, KB
SQUIRES, RR
机构
[1] Department of Chemistry, Yale University, New Haven
关键词
D O I
10.1021/ja00513a009
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The enthalpies and free energies of the acid-catalyzed hydrolysis of a series of alkyl-substituted dimethyl ketals have been determined in a model study of steric effects. The measured enthalpy differences did not correlate with standard quantitative notions of the steric bulk of the substituents, although the overall free-energy changes fit the expected order. The entropy effect of the substituents is a dominant factor in determining the equilibrium composition for this reaction. Possible origins for these entropy effects are discussed. © 1979, American Chemical Society. All rights reserved.
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页码:5512 / 5515
页数:4
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