Diastereoselective Diels—Alder Additions of Ethene to Substituted Homochiral 2(1H)-Pyrazinones.
✍ Scribed by Jo Alen; Wim J. Smets; Liliana Dobrzanska; Wim M. De Borggraeve; Frans Compernolle; Georges J. Hoornaert
- Publisher
- John Wiley and Sons
- Year
- 2007
- Weight
- 26 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0931-7597
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📜 SIMILAR VOLUMES
Variously substituted 2(1H-pyrazinones react with acetylenic derivatives to give specifically substituted pyridones or pyridines. The observed selectivity can be explained in terms of HO-LU interactions for the reagents and two competitive retro Diets-Alder reactions of the primary bicycloadducts. W
Dichloropyrazinones are reacted with alkenolates or a Grignard reagent in order to tether a dienophilic side-chain at the 3-position. The compounds smoothly undergo intramolecular Diels-Alder reaction forming tricyclic ring systems. The reactions proceed completely stereoselective yielding only endo
The C 2 -symmetric, butane diacetal (BDA) auxiliary-based dienes 2 and 3 are described, which display moderate to excellent diastereoselectivities in Diels-Alder reactions with a range of dienophiles under thermal and Lewis acid-catalysed conditions.
Addition of lower or higher order cuprates to the enone homoketals 4a-d give the alkylated products with de's ranging from 12% to 34%. The efftcient production of optically active materials from prochiral precursors by asymmetric induction is one of the goals in synthetic organic chemistry today.1