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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 19, Number 9
BKCSDE 19(9)
September 20, 1998 

 
Title
PM3 Studies on the Acid-Catalyzed Hydrolysis of 1-Phenoxyethyl Propionate
Author
Chan Kyung Kim, In Young Lee, Dong Soo Chung, Bon-SuLee, Ikchoon Lee
Keywords
Abstract
Acid catalyzed hydrolysis of 1-phenoxyethyl propionate, Ⅰ, has been studied using the PM3 method in the gas phase. The first step of the reaction is the protonation of basic sites, three different oxygens in Ⅰ, producing three protonated species Ⅱ, Ⅲ and Ⅳ. All possible reaction pathways have been studied from each protonated structure. Changes in the reaction mechanisms have also been discussed from the results obtained by varying a nucleophile from a water monomer to a water dimer to a complex between one water molecule and an intermediate product (propionic acid or phenol) produced in the preceding unimolecular dissociation processes. Minimum energy reaction pathway is 2-W among the possible pathways, in which water dimer acts as an active catalyst and therefore facilitates the formation of a six-membered cyclic transition state. Lower barrier of 2-W is ascribed to an efficient bifunctional catalytic effect of water molecules. PM3-SM3.1 single point calculations have been done at the gas-phase optimized structure (SM3.1/PM3//PM3) to compare theoretical results to those of experimental work.
Page
993 - 999
Full Text
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