Asymmetric Reactions of 2-Methoxy-1,4-benzoquinones with Styrenyl Systems: Enantioselective Syntheses of 8-Aryl-3-methoxybicyclo[4.2.0]oct-3-en-2,5-diones, 7-Aryl-3-hydroxybicyclo[3.2.1]oct-3-en-2,8-diones, 2-Aryl-6-methoxy-2,3-dihydrobenzofuran-5-ols, and Pterocarpans

doi:10.1021/JO982164S

Paper

Asymmetric Reactions of 2-Methoxy-1,4-benzoquinones with Styrenyl Systems: Enantioselective Syntheses of 8-Aryl-3-methoxybicyclo[4.2.0]oct-3-en-2,5-diones, 7-Aryl-3-hydroxybicyclo[3.2.1]oct-3-en-2,8-diones, 2-Aryl-6-methoxy-2,3-dihydrobenzofuran-5-ols, and Pterocarpans

Published Mar 18, 1999 · T. Engler, M. Letavic, R. Iyengar

Journal of Organic Chemistry

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52

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Abstract

Reactions of 2-methoxy-1,4-benzoquinones 2 and 3 with (E)-propenylbenzenes 1 promoted at −78 °C by Ti(IV)−TADDOLates prepared from diol-(+)-4 afford (1R,6R,7R,8R)-8-aryl-3-methoxy-7-methylbicyclo[4.2.0]oct-3-en-2,5-diones 5/8 or (1R,5R,6R,7R)-7-aryl-3-hydroxy-6-methylbicyclo[3.2.1]oct-3-en-2,8-diones 7/10 in good yield and high ee. (2S,3S)-2-Aryl-6-methoxy-3-methyl-2,3-dihydrobenzofuran-5-ols 6/9 are also found, but in slightly lower ee. Cyclobutanes 5/8 cleanly and efficiently rearrange to the dihydrobenzofurans 6/9 without loss of enantiomeric purity upon treatment with the Ti−TADDOLates at higher temperatures. Reactions of (Z)-propenylbenzene 17 and of indene with 2 and 3 give products in moderate enantiomeric purity. Products obtained from reactions of 1-anisylcycloalkenes with 2 differ significantly in yield and enantiomeric purity. In the latter reactions, the ee's of the cyclobutane products are consistently much higher than those of the dihydrobenzofuran products. More significantly, products of d...

Study Snapshot

2-Methoxy-1,4-benzoquinones with styrenyl systems enable enantioselective synthesis of 8-Aryl-3-methoxybicyclo[4.2.0]oct-3-en-2,5-diones, 7-Aryl-3-

PopulationOlder adults (50-71 years)

Sample size24

MethodsObservational

OutcomesBody Mass Index projections

ResultsSocial networks mitigate obesity in older groups.

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Paper

Asymmetric Reactions of 2-Methoxy-1,4-benzoquinones with Styrenyl Systems: Enantioselective Syntheses of 8-Aryl-3-methoxybicyclo[4.2.0]oct-3-en-2,5-diones, 7-Aryl-3-hydroxybicyclo[3.2.1]oct-3-en-2,8-diones, 2-Aryl-6-methoxy-2,3-dihydrobenzofuran-5-ols, and Pterocarpans

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References

Citations

Stereoselective Synthesis of Flavonoids: A Brief Overview

Stereoselective synthesis of flavonoids enables the obtaining of compounds with biological interest and high enantiomeric purity, using various methodologies and techniques.

Oxathiaborolium-catalyzed enantioselective [2 + 2] cycloadditions.

Oxathiaborolium-catalyzed enantioselective [2 + 2] cycloadditions provide a new efficient route to ring-fused cyclobutanes with quaternary stereogenic centers, offering a new viable synthetic methodology.

Enamides and dienamides in phosphoric acid-catalysed enantioselective cycloadditions for the synthesis of chiral amines.

Enamides and dienamides can be used to synthesize chiral cyclic amines with high enantiocontrol, offering valuable intermediates in organic synthesis.

Catalytic Enantioselective [2+2] Cycloaddition of α-Halo Acroleins: Construction of Cyclobutanes Containing Two Quaternary Stereocenters.

This catalytic method allows for the production of densely functionalized cyclobutanes containing two vicinal quaternary stereocenters in high yield and diastereoselectivity, with potential for synthetic applications.

Organocatalytic Asymmetric Synthesis of Tetrahydrofuran and 1,2-Dihydrobenzofuran Scaffolds

Organocatalysis offers a mild, controlled asymmetric synthesis of substituted tetrahydrofurans and dibenzofurans, with potential applications in pharmaceuticals and biotechnology.

Phosphine-mediated enantioselective [4 + 1] annulations between ortho-quinone methides and Morita–Baylis–Hillman carbonates

Phosphine-catalyzed enantioselective [4 + 1] annulations of ortho-quinone methides and Morita-Baylis-Hillman carbonates provides a facile strategy for the synthesis of biologically important enantioenriched 2,3-

Organocatalytic Asymmetric Formal [3+2] Cycloaddition as a Versatile Platform to Access Methanobenzo[7]annulenes.

This organocatalytic formal [3+2] cycloaddition method allows for the efficient synthesizing of pharmaceutically and structurally important methanobenzo[7]annulenes with excellent enantio- and diastereoselectivities.

Chiral Phosphoric Acid Catalyzed [3 + 2] Cycloaddition and Tandem Oxidative [3 + 2] Cycloaddition: Asymmetric Synthesis of Substituted 3-Aminodihydrobenzofurans.

Chiral phosphoric acid catalysis enables the asymmetric synthesis of 3-amino-2,3-dihydrobenzofurans with excellent yields and diastereoselectivities.