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Acid‐catalyzed hydrolysis of bridged bi‐ and tricyclic compounds. XXXVIII—Kinetics and mechanisms of 1‐ and 3‐nortricyclanols
Author(s) -
Lajunen Martti,
Lahti Veli
Publication year - 2001
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.421
Subject(s) - chemistry , protonation , perchloric acid , cyclopropane , isomerization , kinetic isotope effect , medicinal chemistry , catalysis , hydrolysis , acid catalysis , deuterium , aqueous solution , solvent , kinetics , reaction mechanism , reactive intermediate , ring (chemistry) , organic chemistry , ion , physics , quantum mechanics
The disappearance of 1‐ and 3‐nortricyclanols ( 1‐OH and 2‐OH ) in aqueous perchloric acid was followed by capillary GC at different temperatures and acid concentrations. 1‐OH is ca 1000 times more reactive than 2‐OH . The activation parameters, solvent deuterium isotope effects and parameters of excess acidity equations were measured and the products were studied. Both isomeric nortricyclanols react according to the Ad E 2 mechanism, i.e. the cyclopropane ring is protonated at the rate‐determining stage of the reaction. The protonation causes, in the case of 1‐OH , an isomerization called homoketonization with 2‐norbornanone as the only product and, in the case of 2‐OH , hydration, i.e. the formation of hydroxyl‐substituted norbornyl cations, the fast attack of which by water produces several norbornanediols. Copyright © 2001 John Wiley & Sons, Ltd.