ISSN:
0001-1541
Schlagwort(e):
Chemistry
;
Chemical Engineering
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
Notizen:
A study was made of the epoxidation of octadecenoic acids with peroxybenzoic acid in benzene. Activation energies, frequency factors, enthalpies of activation, entropies of activation, and free energies of activation were obtained for the following fatty acids: cis-9-octadecenoic acid (oleic), trans-9-octadecenoic acid (elaidic), 12-hydroxy-cis-9-octadecenoic acid (ricinoleic), 12-hydroxy-trans-9-octadecenoic acid (ricinelaidic), cis-11-octadecenoic acid (vaccenic), and cis-6-octadecenoic acid (petroselinic). It was observed that the reaction rate was adversely affected by the proximity of the carboxyl group, that is, the closer the carboxyl to the reaction site the lower the rate. A shift from a trans to a cis configuration results in an approximate 50% increase in reaction rate with a corresponding decrease in free energy of activation of 260 cal/mol. The effects of isomerism and the replacement of substituent groups on the reaction rate were generally additive. A mechanism for the peroxydation of octadecenoic acids is proposed.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/aic.690180424
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