An Efficient Synthesis of Highly Functionalised 4-Substituted 2-Azetidinones by a Stereoselective Intermolecular Diels−Alder Reaction of Different Types of 2-Azetidinone-Tethered Dienes
✍ Scribed by Benito Alcaide; Pedro Almendros; Nati R. Salgado; Mari Paz Martínez-Alcázar; Félix Hernández-Cano
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 453 KB
- Volume
- 2001
- Category
- Article
- ISSN
- 1434-193X
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✦ Synopsis
The diastereoselectivity of the intermolecular Diels-Alder reaction of 2-azetidinone-tethered dienes was investigated. Diene precursors were prepared from 4-azetidinone-2-carbaldehydes through an allylation-dehydration process or by the sequence Wittig reaction/enolate trapping. Dienes with a βlactam ring at the allyl carbon of the diene moiety reacted with some acyclic symmetric dienophiles, such as dimethyl acetylenedicarboxylate and dimethyl fumarate, to yield Diels-Alder adducts efficiently in a highly diastereoselective manner. In addition, reaction with an unsymmetrical