Stereochemical studies on the intramolecular diels alder reaction of furans with doubly activated dienophiles.
β Scribed by Laurence M. Harwood; Geraint Jones; John Pickard; Royston M. Thomas; David Watkin
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- French
- Weight
- 338 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
The stereochemical outcome of intramolecular Diels-Alder reactions of furans with Z-and E-2-ene-1,4-dione units attached by a bridging chain to C-2 of the furan results from modification of the steric demands of the bridging chain by the preference of the external activating group to adopt an endostereochemistry.
π SIMILAR VOLUMES
The Intramolecular Diels-Alder reactions of furans possessing a 2-alkyl substituent with a terminal @unsaturated ketone have been surveyed. The consequences of varying the degree of substitution of the furan, the bridging chain length, and position of the activating group on the dienophile upon the
The stereoselectivity of the intramolecular Diels-Alder reactions of terminally activated trienes 4 and 3 increases as the dienophile activating group is changed along the series -CONR2 < -C02Me < -COMe < -Cl-IO. Further increases in selectivity are realized by using Lewis acid catalysts. These res
## Abstract Seven alkyl and aryl substituted __N__βallylβ__N__β(methylfuran)βsulfonamide compounds have been synthesized and their rates of cyclization and equilibrium product concentrations determined. Increased steric bulk on the sulfonamide substituent has been shown to increase both the rate of