Premium
Synthesis of 7,10‐dihydroxy‐8( E )‐octadecenoic acid
Author(s) -
Mhaskar S. Y.,
Subbarao R.
Publication year - 1993
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/bf02542587
Subject(s) - chemistry , double bond , medicinal chemistry , alcohol , ether , wittig reaction , organic chemistry , lithium (medication) , aldehyde , allylic rearrangement , catalysis , medicine , endocrinology
We report the synthesis of 7,10‐dihydroxy‐8( E )‐octadecenoic acid (DOD), which has recently also been reported from bioconversion of oleic acid. One hydroxyl of 1,7‐heptanediol was protected as tetrahydropyranyl ether, and the other hydroxyl was used for chain extension by two carbons via Wittig reaction to give ethyl 9‐tetrahydropyranyloxy‐2( E )‐nonenoate, an α,β‐unsaturated ester, which on Dibal‐H reduction offered allylic alcohol. The epoxidation at the double bond followed by conversion of the hydroxyl group to chloro gave 9‐tetrahydropyranyloxy‐2,3‐oxirane‐1‐chlorononane. Treatment of this epoxy nonyl chloride with excess of LiNH 2 /liquid NH 3 ; followed by addition of 1‐nonanal, gave 18‐tetrahydropyranyloxy‐9, 12‐dihydroxy‐10‐octadecyne. The lithium aluminum hydride reduction of the conjugated hydroxy acetylenic bond, protection of hydroxyl groups as benzoates and oxidation of the primary ether group, followed by removal of benzoate groups, gave DOD.