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The stereochemistry of enzymic hydration and of chemical cleavage of D‐(+)‐ cis ‐12,13‐epoxyoleic acid (Vernolic acid)
Author(s) -
Morris L. J.,
Crouchman M. L.
Publication year - 1969
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02531794
Subject(s) - chemistry , cleavage (geology) , stereochemistry , hydrolysis , nucleophile , enantiomer , acid hydrolysis , organic chemistry , catalysis , geotechnical engineering , fracture (geology) , engineering
The absolute optical configurations of (+)‐ threo ‐12,13‐dihydroxyoleic acid, derived by enzymic hydration of endogenous vernolic acid in crushed Vernonia anthelmintica seed, and of (−)‐ threo ‐12,13‐dihydroxyoleic acid, derived by acetolysis‐hydrolysis of vernolic acid, have been determined. The absolute configuration of the (+)‐enantiomer is L‐12,D‐13‐dihydroxyoleic acid and, as the parent vernolic acid is known to be D‐12,D‐13‐epoxyoleic acid, the stereochemistry of the enzymic hydration is thus shown to involve attack by hydroxyl at the 12 position with inversion at that position. Chemical cleavage of vernolic acid, on the other hand, involves preferential nucleophilic attack, with inversion, at the 13 position.