High Syn Selectivity of a SE′ Reaction: Acylation of an Optically Active 1,1-Disilyl-2-alkene. Preliminary communication
✍ Scribed by Hansjürg Wetter; Paul Scherer; W. Bernd Schweizer
- Publisher
- John Wiley and Sons
- Year
- 1979
- Tongue
- German
- Weight
- 295 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
The disilane/disilylmethane rearrangement of an optically active disilanyl sulfide 9B was used to prepare an optically active disilylalkene 10 whose absolute configuration was established by X‐ray analysis of the bromo derivative 13 (__P__2~1~, a = 7.847 (3) Å, b = 9.487 (3) Å, c = 20.010 (8) Å, β = 82.28° (3), Z = 2). Acylation of 10 furnished an optically active ketone 14, which was degraded to 16, a compound of known absolute configuration. The enantiomeric excess of 10 was determined by alkylation with an optically active lithium compound and that of 14 by an optically active NMR.‐shift reagent. The S~E~′ reaction 10 → 14 was thus shown to proceed with 94% (97% syn/3% anti) stereoselectivity.