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Isomerization of α‐pinene, limonene, α‐terpinene, and terpinolene on sulfated zirconia
Author(s) -
Comelli Nora A.,
Ponzi Esther N.,
Ponzi Marta I.
Publication year - 2005
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-005-1105-2
Subject(s) - isomerization , chemistry , pinene , limonene , camphene , terpene , organic chemistry , catalysis , chromatography , essential oil
Transformations of α‐pinene, limonene, terpinolene, and α‐terpinene were studied in liquid phase on sulfated zirconia having 15% H 2 SO 4 , with the aim of identifing the pathway of α‐pinene isomerization. The principal products obtained in α‐pinene isomerization were camphene, tricyclene, limonene, and terpinolene; the concentration maxima observed at 120°C and 180 min were 53, 6.1, 7.7, and 3.0%, respectively. The principal products formed in the limonene transformation after a 20‐min reaction time were terpinolene, α‐terpinene, and γ‐terpinene; then the concentration of these products decreased. The terpinolene reaction yielded principally m ‐cymenene, whereas the α‐terpinene transformation produced p ‐cymene. Studies of the initial rates of transformation of terpenes indicate a very high rate for α‐pinene, intermediate for limonene and α‐terpinene, and very low for terpinolene. The scheme proposed to interpret the results of the α‐pinene isomerization reaction on sulfated zirconia is in agreement with reaction schemes proposed by A. Allahverdiev, S. Irandoust, and D. Y. Murzin (Isomerization of α‐Pinene over Clinoptilolite.