Synthesis of enantiomerically pure (S)-3-trichloromethylbutyric acid via asymmetric conjugate addition of trichloromethyl metal compounds to a chiral enoate. Activation effect of a sulfonylamino group
✍ Scribed by Günter Helmchen; Günter Wegner
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- French
- Weight
- 253 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
+)(S)-3-Trichloromethylbutyric acid, a building block for syntheses of various marine natural products, can be prepared via 99:l stereoselective conjugate addition of C13CMgC1 to the crotonate of a chiral auxiliary containing a sulfonylamino substituent. Recently several polychlorinated metabolites derived from amino acid precursors have been isolated from the sponge Dysidea herbacea: dysidenin 3a , isodysidenin 3b , dysidin 3c , and related 3d compounds . Common structural features suggested the use of (t)(S)-3-trichloromethylbutyric acid t(S)-11 as starting material for their synthesis4, as is illustrated by the following retrosynthetic scheme for dysidenin: DYSIDENIN5