ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Viridiene ((+)-6; (+)-(3R,4S)-3-((1Z)-1,3-butadienyl)-4-vinylcyclopentene) and aucantene ((+)-18; (+)-(4R,5R)-4-((1E)-1-propenyl)-5-vinylcyclohexene) are constituents of the pheromone bouquets of several brown algae species. Key synthons to the title compounds are optically active γ-lactones with known or experimentally determined absolute configurations. Horse liver alcohol dehydrogenase, which catalyses the oxidation of meso- and racemic non-meso diols to chiral lactones, and pig-liver esterase, which catalyzes the saponification of meso-diesters to chiral half-esters, were utilized for the asymmetric synthesis of such precursors. The racemic non-meso diol rac-1 is converted to the two stereoisomeric γ-lactones (+)-2 and (+)-3 which are readily separated. meso-Diol 12 is oxidized to the chiral γ-lactone (-)-11. Its enantiomer (+)-11 is obtained by enantioselective saponification of the meso-diester 9 with pig-liver esterase. Appropriately designed syntheses lead from these chiral intermediates to both enantiomers (+)- and (-)-6 of viridiene and (+)- and (-)-18 of aucantene. In addition, kinetically controlled reduction of the racemic aldehydes rac-5a and rac-15 with horse liver alcohol dehydrogenase offers a convenient alternative to the enantioselective preparation of the enantiomers of the two hydrocarbons 6 and 18. Chromatography of 6 on triacetylated cellulose as a stationary chiral phase confirms the enantiospecificity of the synthetic routes designed.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19850680731
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