Isolation, Identification, and Enantioselective Synthesis of Octane-1,3,7-triol:  Determination of Its Absolute Configuration

Abstract

Extracts obtained by solid-phase extraction from apples were separated by multilayer countercurrent chromatography. In the most polar fractions, the novel octane-1,3,7-triol was identified by 1H and 13C NMR as well as LC-MS and by comparison with the synthesized racemic reference compound. Resolution of the enantiomers was achieved after acetylation of the triol followed by GC separation. The enantioselective synthesis of the stereoisomers of octane-1,3, 7-triol was performed using the building blocks (R)- and (R, S)-butane-1,3-diol and (S)- and (R,S)-butane-1,2,4-triol. Comparison with the isolated products indicated that the natural compound consisted of a mixture of (3R,7S)- and (3R,7R)-octane-1,3,7-triol in a ratio of 2:3. Since the C3 chiral center is enantiomerically pure, the triol might be biogenetically related to the known antimicrobial (R)-(+)-octane-1,3-diol, the major volatile compound of some apple cultivars.

Absolute configuration of 3‐hydroxy acids formed by Stenotrophomonas maltophilia: Application of multidimensional gas chromatography and circular dichroism spectroscopy

“…Thus, (6Z)-3-hydroxy-6-dodecenoic acid (1a), a product of the bioconversion of linoleic acid, was converted without loss of stereochemical information into its corresponding saturated 1,3-diol (1d) by hydrogenation to (1c) and subsequent reduction of the carboxylic group 19,20 (Fig. 1).…”

Novel 1,3-Dioxanes from Apple Juice and Cider

“…(R,S)-Octane-1,3-diol [(R,S)-1] and (R,S)-5(Z)-octene-1,3-diol [(R,S)-3] were synthesized by LiAlH 4 reduction of their respective 3-oxo ethyl esters, whereas (R)octane-1,3-diol [(R)-1] and (R)-5(Z)-octane-1,3-diol [(R)-3] were obtained by Sharpless epoxidation of their allylic alcohols using (+)-diethyl tartrate as the chiral ligand (Dietrich et al, 1997). The synthesis of (3R,7R)-and (3R,S,7R,S)-octan-1,3,7-triol denoted, respectively, as [(3R,7R)-and (3R,S,7R,S)-2) has been reported recently (Beuerle et al, 1999). The (4R,S,2R,S) stereoisomers of 4-10, 12-20, and 22 were obtained by the reaction of racemic 1,3-diols with the aldehydes or ketones, and (4R,2R,S) diastereomers were formed from (3R)-diols and the aldehydes or ketones.…”

“…French apple varieties (Beuerle et al, 1996) used for cider production contain large amounts of 1 and 3, and 2 was recently identified in the variety Peau de Chien (Beuerle et al, 1999). Because yeast (Dittrich, 1987) and apples (Paillard, 1990) produce a number of aldehydes such as propanal, butanal, 2-methylpropanal, hexanal, 3-methylbutanal, and 2-methylbutanal, as well as the ketones acetone and 2-butanone, we expected the occurrence of 1,3-dioxanes derived from 1,3-diols and these carbonyl compounds in apples and cider.…”

Selective (R)‐3‐hydroxylation of FA by Stenotrophomonas maltophilia

“…3). Stereochemical evaluation was carried out by MDGC after transformation of the 3-hydroxylated microbial products into the corresponding saturated 1,3-diols by hydrogenation and subsequent reduction of the carboxylic function with LiAlH 4 (27) and comparison with reference data. A racemic reference substance was synthesized by aldol addition with methyl acetate and subsequent hydrogenation, followed by reduction of the methyl ester with LiAlH 4 (27).…”

“…Stereochemical evaluation was carried out by MDGC after transformation of the 3-hydroxylated microbial products into the corresponding saturated 1,3-diols by hydrogenation and subsequent reduction of the carboxylic function with LiAlH 4 (27) and comparison with reference data. A racemic reference substance was synthesized by aldol addition with methyl acetate and subsequent hydrogenation, followed by reduction of the methyl ester with LiAlH 4 (27). Enantioselective synthesis of (S)-dodecane-1,3-diol was carried out by asymmetric epoxidation under Sharpless conditions (28) and treatment of the epoxide formed with sodium bis(2-methoxy-ethoxy)aluminum (Red-Al) (29).…”