Yeast Reduction Products Research Articles

Syntheses of (S)- and (R)-dihydromethysticin from two yeast-reduction products, which can be prepared from one racemic compound

Biologically active (S)-Dihydromethysticin ((S)-1) with high enantiomeric purity (>99%ee) was synthesized from the optically active yeast-reduction product, (1 R,2 S)-methyl 2-hydroxycyclohexyl acetate (2), through the introduction of the 3,4-methylenedioxybenzyl group, Beayer-Villiger oxidation, and conversion to its enolate. Moreover, (R)-Dihydromethysticin ((R)-1) with high enantiomeric purity (>99%ee) was synthesized from the optically active yeast-reduction product, (1 S,5 S)− 2-oxabicyclo[3.3.0]octan-3-one (3), employing the same synthetic method used for (S)-1. The antifungal activity of both these enantiomers against Colletotricum lagenarium and Bipolaris oryzae was found to be weak.

Syntheses of Natural Compounds from Yeast-reduction Products of Cyclic γ-Keto Ester and Application to Agrichemicals

Syntheses of Natural Compounds from Yeast-reduction Products of Cyclic γ-Keto Ester and Application to Agrichemicals

Syntheses and Phytotoxicity of All Stereoisomers of 6-(2-Hydroxy-6-phenylhex-1-yl)-5,6-dihydro-2H-pyran-2-one and Determination of the Effect of the α,β-Unsaturated Carbonyl Structure and Hydroxy Group Bonding to Chiral Carbon.

All four stereoisomers of naturally occurring 6-(2-hydroxy-6-phenylhex-1-yl)-5,6-dihydro-2H-pyran-2-one (1) were synthesized by employing yeast-reduction products with high optical purity [from 95% enantiomeric excess (ee) to more than 99% ee], and then their phytotoxicities against lettuce and Italian ryegrass were evaluated. In the Italian ryegrass seedlings test, (6S,2'R)-1 showed the most potent and stereospecific activity against the shoots (IC50 = 260 μM) and roots (IC50 = 43.2 μM), with a significant difference from other stereoisomers. The highest seed germination inhibitory activity against Italian ryegrass seed was also observed in (6S,2'R)-1, showing a 53% germination ratio from the control at 1000 μM. This advantageous (6S,2'R) stereochemistry was employed in the syntheses of α,β-dihydro, 2'-dehydroxy, and 2'-methoxy derivatives 13-15. By the test using these derivatives, the importance of the α,β-unsaturated double bond and hydroxy group bonding to a chiral center on the 6-alkyl chain of 5,6-dihydro-α-pyrone for phytotoxicity was determined. In the test against lettuce, the 6S configuration and (6S,2'S) configuration were necessary for growth inhibition (IC50 = ca. 60 μM) and germination inhibition (63% germination ratio at 1000 μM), respectively.

Stereoselective syntheses of cryptocarya diacetate and all its stereoisomers in optically pure forms.

Cryptocarya diacetate and each of its stereoisomers were stereoselectively synthesized in 8-16 steps. One of the three chiral carbons was converted from the chiral center of a yeast-reduction product. The other two chiral carbons were constructed by employing stereoselective allylation and syn-and anti-1,3-reductions. The enantiomeric excesses of the synthesized cryptocarya diacetate and its stereoisomers were determined to be more than 99%ee using a chiral column.

Total Syntheses of (−)- and (+)-Boronolide and Their Plant Growth-Inhibitory Activity

Optically pure (+)- and (-)-boronolides were stereoselectively synthesized from yeast reductive products which had been obtained by yeast reduction of one common racemic substrate. The lactone structure of boronolide was constructed by Baeyer-Villiger oxidation. The stereochemistry of the yeast reduction products was studied to obtain the stereocenters at 5 positions of the dodecanolides of (+)- and (-)-boronolides. The stereochemistry of the 6 and 7 positions was obtained by AD-mix-α or β oxidation. The chiral center at the 8 position was constructed by employing (R)-(+)- or (S)-(-)-2-methyl-CBS-oxazaborolidine reduction or the Mitsunobu reaction. The plant growth-inhibitory activity against Echinochloa crusgalli L. of naturally occurring (+)-boronolide was higher than that of the (-)-boronolide.

Syntheses of All Stereoisomers of Goniodiol from Yeast-Reduction Products and Their Antimicrobiological Activity

All stereoisomers of goniodiol were synthesized from yeast-reduction products. The C-6 chiral centers were converted from the chiral centers of the yeast-reduction products. Stereoselective conversion of the alkene, which had been prepared from the yeast-reduction product, to glycol constructed the C-7 and C-8 stereochemistry. (+)-Goniodiol and 7-epi-(+)-goniodiol showed the highest antibacterial activity (MIC, 3.1 mM) against Yersinia intermedia.

Synthesis of a Glandular Secretion of the Civet Cat, (2S,6S)-(6-Methyltetrahydropyran-2-yl)acetic Acid and Its Enantiomer, by Using the Yeast-Reduction Product and Recovered Substrate from Yeast Reduction

A glandular secretion of the civet cat, (2S,6S)-(6-methyltetrahydropyran-2-yl)acetic acid 1 and its enantiomer, were synthesized from the yeast-reduction product and recovered substrate from yeast reduction.

ChemInform Abstract: Novel Chiral Building Blocks Derived from Baker′s Yeast Reduction Products: Synthesis and Odor of Mono‐ and Bicyclic Macrolides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Novel chiral building blocks derived from Baker's yeast reduction products: Synthesis and odour of mono- and bicyclic macrolides

A number of bicyclic macrolides with two stereogenic centres formally derived from ω-cycloalkyl fatty acids were synthesised by ring enlargement of cycloalkanones with novel chiral building blocks, easily available from yeast reduction products of β-keto esters. A comparison with structurally related monocyclic macrolides revealed surprising effects of structural variations on the olfactory properties.

Total synthesis of (−)-slaframine from (2R,3S)-3-hydroxyproline

D. W. Knight and A. William Sibley, J. Chem. Soc., Perkin Trans. 1, 1997, 2179 DOI: 10.1039/A701878I

Absolute stereochemistry of yeast reduction products from 2-(3',4'-dimethoxy-cinnamyl)-2-methylcyclopentane-1,3-dione.

The absolute stereochemistry of yeast reduction products 2s and 2a from 2-(3',4'-dimethoxy-cinnamyl)-2-methylcyclopentane-1,3-dione (1) was investigated. The results from several spectral studies and chemical correlations enabled their absolute configurations to be concluded as (2S,3S) and (2R,3S), respectively.

An alternative approach to mevinic acid analogues from methyl (3R)-(–)-3-hydroxyhex-5-enoate and an extension to unambiguous syntheses of (6R)-(+)-and (6S)-(–)-goniothalamin

Ozonolysis of the 3-silyloxyhexenoate 12, derived from the yeast reduction product methyl (3R)-(–)-3-hydroxyhex-5-enoate 6 and having an enantiomeric enrichment of 78%, followed by Wittig homologation and selenolactonization leads to the unsaturated mevinic acid analogues 17 and 18. Subsequent dehydration gives both enantiomers of the natural product goniothalamin 20 and 21.

Total syntheses of natural (+)-(4R,6R)-4-hydroxy-6-pentylvalerolactone and of (–)-(6R)-massoialactone

An asymmetric total synthesis and hence a confirmation of the absolute configuration of naturally occurring (+)-(4R,6R)-4-hydroxy-6-pentylvalerolactone 10, a metabolite of Cephalosporium recifei, is described, starting from the yeast reduction product methyl (3R)-3-hydroxyhex-5-enoate 5. The key step is a highly trans-selective kinetic iodolactonization of the unsaturated acid 16e. Dehydration of the lactone 10 leads to natural (–)-(6R)-massoialactone 11.

An Alternative Approach to Mevinic Acid Analogues from Methyl (3 [formula omitted])-3-Hydroxy-5-Hexenoate and an Extension to Rational Syntheses of (+)-(6 [formula omitted])-Goniothalamin and its Non-natural (-)-(6 [formula omitted])-Enantiomer

The chiral mevinic acid analogues [(15) and (16)] have been prepared from the yeast reduction product (2) by homologation and selenolactonistion and subsequently converted into both enantiomers of Goniothalamin [(17) and (18)].

Use of a thermally stable, optically active nitrile oxide in the synthesis of a lyngbyatoxin A intermediate

The synthesis of a homochiral nitrile oxide from a baker's yeast reduction product and its use in the preparation of a lyngbyatoxin A intermediate are detailed.