Diastereoselective aldol condensations of tin enolates with aldehydes
โ Scribed by Sharada Shenvi; J.K. Stille
- Publisher
- Elsevier Science
- Year
- 1982
- Tongue
- French
- Weight
- 218 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0040-4039
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โฆ Synopsis
The reaction of tin enolates of cyclohexanone or propiophenone with benzaldehyde at -78'C gives predominately the threo aldol diastereomer.
๐ SIMILAR VOLUMES
Both (g)-and @)-zirconium enolates have been shown to undergo selective kinetic aldol condensation to give mainly erythro-a-hydroxy ketones, esters and amides.
The a-hydroxyglycine 1 -readily accessible from glyoxylic acid hydrate and benzyl ~arbaminate[~I---was converted into the ethyl ether 2. Successive reaction with PCI3 and triethyl phosphite led to ethyl 2-benzyloxycarbonylamino-2-diethyloxyphosphorylacetate 3 (yield 80%). N-Acyl-2-(diethyloxyphospho
A chelation-controlled and highly diastereoselective synthesis of syn-aldols is described. Aldol reaction of (S)-valinolderived ester with a variety of aldehydes proceeded with high syn-diastereoselectivities (up to 99:1) and isolated yields (94%).