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Cyclopinolenic acids: Synthesis, derivatives and thermal properties
Author(s) -
Hase A.,
Kaltia S.,
Matikainen J.,
AlaPeijari M.,
Hase T.
Publication year - 1992
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/bf02541071
Subject(s) - isomerization , chemistry , intramolecular force , cis–trans isomerism , stereochemistry , medicinal chemistry , organic chemistry , catalysis
The two isomeric cyclopinolenic acids (CP‐1 and CP‐2), components of distilled tall oil, have been synthesized by means of an intramolecular Diels‐Alder reaction of isomers of 5,10,12‐octadecatrienoic esters, themselves synthesized in a stereocontrolled manner. The 5 cis ,10‐ trans ,12 trans isomer cyclizes at 200°C to a 1:3 mixture of esters of CP‐1 and CP‐2. At 200°C, the 5 cis ,10 trans ,12 cis isomer is unreactive, but at 240°C it gives the same CP‐1 + CP‐2 ester mixture, presumably by way of prior isomerization to the 5 cis ,10 trans ,12 trans isomer. A subambient thermal study of CP‐1 and CP‐2 and their derivatives shows that the compounds, excluding CP‐1, lack crystalline structures or melting points, and display glass transitions only, below −80°C for esters and below −50°C for the carboxylic acids.