The Preparation and Properties of the Eight Diastereoisomers of 9,10,12,13-Tetrahydroxystearic Acid

Abstract

The eight diastereoisomers of 9,10,12,13-tetrahydroxystearic acid were prepared from a -linoleic acid (cis-9-cis-12-octadecadienoic acid). A new method of preparation was developed which establishes the spacial relationships of the hydroxyl groups in each diastereoisomer.Hazura (1) was the first to isolate a 9,10,12,13-tetrahydroxystearic acid (sativic acid) from the alkaline potassium permanganate oxidation of linoleic acid.Further study (2)(3)(4)(5)(6) of this oxidation reaction resulted in methods for improving the yield and it is now established that two diastereoisomers of the tetrahydroxystearic acid are formed in this reaction. The melting points of these acids are 173°( I) and 164°( II). The more soluble one has also been reported to melt at 157-159°, but according to Riemenschneider et al. ( 7) this is an eutectic mixture of the «-and jS-sativic1 acids melting at 173°and 164°. Nicolet and Cox (8) obtained two different diastereoisomers of 9,10,12,13-tetrahydroxystearic acid by treating linoleic acid with hypochlorous and hypobromous acids to form the dichloroand dibromo-dihydroxystearic acids. Replacement of the halogen atoms by hydroxyl groups gave two tetrahydroxystearic acids melting at 145°a nd 135°. Later work suggests that these acids are the same as the two diastereoisomers obtained in the peracetic acid oxidation of linoleic acid (9), or the alkaline potassium permanganate oxidation of linolelaidic acid (10) which are now described as melting at 146°( III) and 126°or 122°( IV). Kass and Burr (10) prepared a third set of diastereoisomers of 9,10,12,13-tetrahydroxystearic acid by the alkaline potassium permanganate oxidation of the trans-cis or cis-trans geometric isomer of linoleic acid. The melting points of these acids are given as 156-158°( V) and 126°( VI). The melting point of the former has now been raised to 164°. A seventh diastereoisomer of tetrahydroxystearic acid was re-1. A method is described for the preparation of the eight diastereoisomers of 9,10,12,13-tetrahydroxystearic acid from -linoleic acid. The special arrangements of the hydroxyl groups in each diastereoisomer are deduced from this method of preparation.2. Two new fatty acids cis-and trans-9,10-dihydroxy-12-octadecenoic acid are also described.3. The present system of nomenclature applied to the tetrahydroxystearic acids is discussed.

Bioactive Constituents of the Seeds of Brucea javanica

“…Full 1 H-and 13 C-NMR data of 2 have been assigned for the first time based on its 2D-NMR spectra ( 1 H-1 H COSY, HMQC, HMBC). [19], ()-8-hydroxyhexadecanoic acid [20], and vanillin, have also been isolated along with compounds 1 and 2. Their structures were identified by physical and spectroscopic methods (m. p., [a] D , MS, 1 H-and 13 C-NMR) and by comparing the data obtained with those of published values.…”

Improved preparation of 9,10,12,13‐tetrahydroxystearic acids fromanti‐cis,cis‐9,10,12,13‐diepoxystearic acid

“…When 88% formic acid is used, the yield drops to 50-55%. It seems clear now that earlier workers, unaware of the importance of the role of water, could not have obtained higher yields of THSA, because the diepoxystearic acids, prepared from linoleic acid, were treated with dilute aqueous formic or acetic acids in the initial ring opening step (6)(7)(8)(9). Mechanisms and stereochemistry : Nucleophilic attack by DMSO or formic acid (Schemes 3 and 4) on protonated anti-cis,cis-9,10,12,13-diepoxystearic acid (A-DESA) can occur by four different pathways to give two (and only two) isomeric di(hydroxy-aikoxysulfonium) salts or di(hydroxy-formates), respectively: (a) attack on the two most widely separated oxirane carbon atoms (9,13) with trans ring opening (inversion), (b) attack on the two closest oxirane carbon atoms (10,12) with trans ring opening (inversion), (c) attack on oxirane carbon atom (10) and oxirane carbon atom (13) with trans ring opening (inver-Non), and (d) attack on oxirane carbon atom (12) and oxirane carbon atom (9) with trans ring opening (inversion).…”

“…Among long chain diepoxides, the acid-catalyzed hydrolysis of 9,10,12, 13-diepoxystearic acid derived from linoleic acid has long been of continuing interest to lipid chemists (6)(7)(8)(9). Yields of 9,10,12,13-tetrahydroxystearic acids (THSA) of only 6-16% have been obtained from linoteic acid on reaction with hydrogen peroxide and acetic (6) or formic acid (7-9) followed by hydrolysis (Scheme 1).…”

Hyperbranched polyesters by polycondensation of fatty acid-based ABn-type monomers

“…The low yield in the latter case could be explained by the hydroxylation of methyl ricinoleate which resulted in a mixture of four diastereoisomers, only one of them being able to crystallize. [42][43][44][45] The structure of the so-formed AB 2 -or AB 3 -type monomers was assessed by 1 H NMR spectroscopy (see ESI Figure S1). GC analyses revealed a chemical purity higher than 94% in all cases.…”